All
All
Appliances
Automotive
Bath
Building Materials
Cleaning
Doors & Windows
Electrical
Flooring
Furniture
Hardware
Health And Wellness
Heating, Venting & Cooling
Holiday Decorations
Home Decor
Industrial & Scientific
Kitchen
Lighting
Lumber & Composites
Musical Instruments
Other
Outdoors
Paint
Playground Sets
Plumbing
Safety Equipment
Smart Home
Sports & Outdoors
Storage & Organization
Tools
Window Treatments
Workwear
EN
Select the country/region, language, and currency you prefer for shopping.
Country Website
Language
Currency
Submit
Delivery to
Your Address
Hello, Sign in
Account & Order
Categories
Deals
New
Best Sellers
Clearance
Inspiration
Member Club
Download VEVOR App
Exclusive
AU $5.00
off for your first three orders on the App.
Scan the QR code to download
Home
Automotive
Shop Equipment
Underhoist Stand
Search for "
three ton jack
"
Automotive
Outdoors
Tools
Sports & Outdoors
Furniture
Hardware
Musical Instruments
Building Materials
Kitchen
50 Results
Sort by:
Popular
Popular
Price from Low to High
Price from High to Low
Hot
New
Categories
Automotive
Manual Trailer Jack Without Wheels
Outdoors
Fuel Pizza Stove
Tools
Safe Boxes
Sports & Outdoors
Poker Chips
Furniture
Fabric Triple Sofa and Other Straight Sofas
Hardware
Wire Rope
Musical Instruments
Cajon
Building Materials
Drywall Lifts
Kitchen
Pizza Stones
Price Discounts
On Sale
Bulk Savings
Stars
5 stars only
4 stars and up
3 stars and up
2 stars and up
1 star and up
Price
Go
30
~
50
50
~
100
100
~
200
200
~
500
500
&
Above
In Stock
Pickup
Quick look
VEVOR Underhoist Support Stand, 3/4 Ton Capacity Under Hoist Jack Stand, Lifting from 38.4 to 75.4 in, Bearing Mounted Spin Handle, Self-Locking Threaded Screw, Two Wheels, Support Vehicle Components
(2)
98.9
98.9
Deal after registering
Member discounted price
0% cash back
at checkout.
98.9
Non-PRO Account
98.9
Save
Non-PRO Account
In Stock.
Add to Cart
Quick look
VEVOR Underhoist Support Stand, 3/4 Ton Capacity Under Hoist Jack Stand, Lifting from 52.8 to 76 in, Self-Locking Threaded Screw, Bearing Mounted Spin Handle Pole Jack, Support Vehicle Components
95.9
95.9
Deal after registering
Member discounted price
0% cash back
at checkout.
95.9
Non-PRO Account
95.9
Save
Non-PRO Account
In Stock.
Add to Cart
VEVOR Strut Spring Compressor, 4.5 Ton/9920 LBS Hydraulic Jack Capacity, 1 Ton Rated Compression Force, Auto Strut Coil Spring Compressor Tool, Hydraulic Spring Compressor for Strut Spring Removing
(74)
230.9
230.9
Deal after registering
Member discounted price
0% cash back
at checkout.
230.9
Non-PRO Account
230.9
Save
Non-PRO Account
In Stock.
Add to Cart
VEVOR 4 Ton Porta Power Kit, Portable Hydraulic Jack with 3.9 ft/1.2 m Oil Hose, Auto Body Frame Repair Kit with Storage Case for Car Repair, Truck, Farm (8800 LBS)
(77)
152.9
152.9
Deal after registering
Member discounted price
0% cash back
at checkout.
152.9
Non-PRO Account
152.9
Save
Non-PRO Account
In Stock.
Add to Cart
Quick look
VEVOR Hydraulic Bottle Jack, 20 Ton (44092 lbs) Load Capacity, 225-435 mm Lifting Range, Heavy Duty Welded Bottle Jack for Car, SUV, Pickup, Auto Repair, House Lift and Agricultural Equipment, Orange
(13)
74.9
74.9
Deal after registering
Member discounted price
0% cash back
at checkout.
74.9
Non-PRO Account
74.9
Save
Non-PRO Account
Only 5 Left, order soon
Add to Cart
Quick look
VEVOR 12 Ton Porta Power Kit, Portable Hydraulic Jack with 4.6 ft/1.4 m Oil Hose, Auto Body Frame Repair Kit with Storage Case for Car Repair, Truck, Farm
(77)
248.9
248.9
Deal after registering
Member discounted price
0% cash back
at checkout.
248.9
Non-PRO Account
248.9
Save
Non-PRO Account
In Stock.
Add to Cart
Quick look
VEVOR Hydraulic Cylinder Jack, 20 Ton Solid Ram Hydraulic Cylinder, 6 Inch Stroke Single Acting Hydraulic Cylinder, with Quick Connector Portable Hydraulic Solid Jack Hydraulic Lifting Cylinders
(3)
124.9
124.9
Deal after registering
Member discounted price
0% cash back
at checkout.
124.9
Non-PRO Account
124.9
Save
Non-PRO Account
Only 2 Left, order soon
Add to Cart
Quick look
VEVOR 30Ton 10.16 cm Stroke Hollow Hydraulic Cylinder Jack 29937 Lift Cylinder Industrial Durable Automotive Body Bending
(5)
253.9
253.9
Deal after registering
Member discounted price
0% cash back
at checkout.
253.9
Non-PRO Account
253.9
Save
Non-PRO Account
In Stock.
Add to Cart
Quick look
VEVOR 12 Ton Porta Power Kit, Hydraulic Ram with Pump with 1.4 m Oil Hose, Portable Hydraulic Jack with Storage Case for Automotive, Garage, Farm, Mechanic
(77)
267.9
267.9
Deal after registering
Member discounted price
0% cash back
at checkout.
267.9
Non-PRO Account
267.9
Save
Non-PRO Account
In Stock.
Add to Cart
Clearance
Quick look
VEVOR Farm Jack, 152.5 cm Utility High Lift Farm Jack, 3.18 Ton Capacity Ratcheting Off Road Utility Jacks, Heavy-Duty Lift Jacks with 130.1-1380 mm Lifting Range for Tractor, Truck, SUV
(3)
152.9
152.9
Deal after registering
Member discounted price
0% cash back
at checkout.
152.9
Non-PRO Account
152.9
Save
Non-PRO Account
Almost sold out
Add to Cart
Quick look
VEVOR 10 Ton Porta Power Kit, Portable Hydraulic Jack with 4.6 ft/1.4 m Oil Hose, Auto Body Frame Repair Kit with Storage Case for Car Repair, Truck, Farm
(77)
226.9
226.9
Deal after registering
Member discounted price
0% cash back
at checkout.
226.9
Non-PRO Account
226.9
Save
Non-PRO Account
In Stock.
Add to Cart
Quick look
VEVOR Underhoist Support Stand, 3/4 Ton Capacity Under Hoist Jack Stand, Lifting from 1320 mm to 2032 mm, Bearing Mounted Spin Handle, Foot Pedal Adjustment, Stable Base, Support Vehicle Components
119.9
119.9
Deal after registering
Member discounted price
0% cash back
at checkout.
119.9
Non-PRO Account
119.9
Save
Non-PRO Account
Only 2 Left, order soon
Add to Cart
VEVOR 20 Ton Porta Power Kit, Portable Hydraulic Jack with 4.6 ft/1.4 m Oil Hose, Car Frame Repair Tool with Storage Case for Automotive, Heavy Equipment, Mechanic (44000 LBS)
(77)
406.9
406.9
Deal after registering
Member discounted price
0% cash back
at checkout.
406.9
Non-PRO Account
406.9
Save
Non-PRO Account
In Stock.
Add to Cart
Quick look
VEVOR Hydraulic Bottle Jack, 12 Ton (26455.5 lbs) Capacity, 205-400 mm Lifting Range, Heavy Duty Welded Bottle Jack for Car, SUV, Pickup, Auto Repair, House Lift and Agricultural Equipment, Orange
(13)
58.9
58.9
Deal after registering
Member discounted price
0% cash back
at checkout.
58.9
Non-PRO Account
58.9
Save
Non-PRO Account
In Stock.
Add to Cart
Quick look
VEVOR 30T/66000LBS Hollow Hydraulic Cylinder Jack 50 mm Plunger Ram Hydraulic Solid Cylinder Hydraulic Jack for Car/Van/Boat/Truck/Caravan
(5)
192.9
192.9
Deal after registering
Member discounted price
0% cash back
at checkout.
192.9
Non-PRO Account
192.9
Save
Non-PRO Account
Only 1 Left, order soon
Add to Cart
Quick look
VEVOR Underhoist Support Stand, 1 Ton Capacity Under Hoist Jack Stand with Handle, Adjustable Height, Bearing Mounted Spin Handle, Self-Locking Threaded Screw, Stable Base, Support Vehicle Components
165.9
165.9
Deal after registering
Member discounted price
0% cash back
at checkout.
165.9
Non-PRO Account
165.9
Save
Non-PRO Account
Only 4 Left, order soon
Add to Cart
Quick look
VEVOR Double Doors 5.5 cu.ft Safe Box with Key Lock & Password, Safe Lock Box with Fireproof Bag, Key Rack, LED Light, 2 Height Adjustable and Removable Divider and 1 Cabinet for Money, Documents, Jewelry and Valuables, Black
(13)
441.9
441.9
Deal after registering
Member discounted price
0% cash back
at checkout.
441.9
Non-PRO Account
441.9
Save
Non-PRO Account
Almost sold out
Add to Cart
Quick look
VEVOR Double Doors 7.2 cu.ft Safe Box with Key Lock & Password, Safe Lock Box with Fireproof Bag, Key Rack, LED Light and 2 Height Adjustable and Removable Divider for Money, Documents, Jewelry and Valuables, Black
(13)
481.9
481.9
Deal after registering
Member discounted price
0% cash back
at checkout.
481.9
Non-PRO Account
481.9
Save
Non-PRO Account
In Stock.
Add to Cart
Quick look
VEVOR Pizza Stone, 508 x 355 mm Rectangular Cordierite Pizza Stone, Extra Large Baking-Stone with PP Scraper, 17 mm Thick Heat-Resistant Cordierite, for Oven, Baking Bread & Pizzas, BBQ Grilling
(3)
46.9
46.9
Deal after registering
Member discounted price
0% cash back
at checkout.
46.9
Non-PRO Account
46.9
Save
Non-PRO Account
Only 1 Left, order soon
Add to Cart
Quick look
VEVOR Double Doors 4.5 cu.ft Safe Box with Key Lock & Password, Safe Lock Box with Fireproof Bag, Key Rack, LED Light and 2 Height Adjustable and Removable Divider for Money, Documents, Jewelry and Valuables, Black
(13)
305.9
305.9
Deal after registering
Member discounted price
0% cash back
at checkout.
305.9
Non-PRO Account
305.9
Save
Non-PRO Account
In Stock.
Add to Cart
Quick look
VEVOR 304 Stainless Steel Cable 4.76mm 7 X 19 Steel Wire Rope 7620cm Steel Cable for Railing Decking DIY Balustrade
(51)
101.9
101.9
Deal after registering
Member discounted price
0% cash back
at checkout.
101.9
Non-PRO Account
101.9
Save
Non-PRO Account
Only 4 Left, order soon
Add to Cart
Quick look
VEVOR Double Doors 3.5 cu.ft Safe Box with Key Lock & Password, Safe Lock Box with Fireproof Bag, Key Rack, LED Light and 2 Height Adjustable and Removable Divider for Money, Documents, Jewelry and Valuables, Black
(13)
308.9
324.9
Deal after registering
Member discounted price
0% cash back
at checkout.
308.9
Non-PRO Account
308.9
Save
Non-PRO Account
In Stock.
Add to Cart
Quick look
VEVOR Cajon Box Drum, with Internal Snare Wires, Lightweight Wooden Percussion Box, Portable Birch Wood Drum Musical Instrument with Silicone Feet, for Beginners and Professionals, 305 x 305 x 430 mm
109.9
109.9
Deal after registering
Member discounted price
0% cash back
at checkout.
109.9
Non-PRO Account
109.9
Save
Non-PRO Account
Only 5 Left, order soon
Add to Cart
Quick look
VEVOR Pizza Oven Outdoor, 12" Pellet Pizza Oven, Portable Pizza-Stove with Built-in Thermometer, Wood Fired Stainless Steel Pizza-Maker, for Backyard, Camping, Pizza-Stone, Shovel, Carry Bag, Silver
(12)
150.9
150.9
Deal after registering
Member discounted price
0% cash back
at checkout.
150.9
Non-PRO Account
150.9
Save
Non-PRO Account
In Stock.
Add to Cart
Quick look
VEVOR Drywall Lift, Heavy-Duty 68 kg Sheetrock Hoist for Wall Installation, One Person Drywall Installation, 1219x4878 mm Max. Panel Vertical Lifter with Wheels, Easy Transport (Yellow)
462.9
462.9
Deal after registering
Member discounted price
0% cash back
at checkout.
462.9
Non-PRO Account
462.9
Save
Non-PRO Account
Almost sold out
Add to Cart
Quick look
VEVOR 3 Steater Sofa, Modular Sectional Couch with Bottom Storage Space, Modern Comfy Cloud Sofa with Side Storage Pockets and Metal Frame, Ideal for Living Room, Bedroom, Apartment and Office, White
918.9
918.9
Deal after registering
Member discounted price
0% cash back
at checkout.
918.9
Non-PRO Account
918.9
Save
Non-PRO Account
Only 1 Left, order soon
Add to Cart
Quick look
VEVOR Farm Jack with Base, 152.5 cm Utility High Lift Farm Jack, 3.18 Ton Capacity Ratcheting Off Road Utility Jacks, Heavy-Duty Lift Jacks with 130.1-1380 mm Lifting Range for Tractor, Truck, SUV
(3)
182.9
174.99
Deal after registering
Member discounted price
0% cash back
at checkout.
182.9
Non-PRO Account
182.9
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR 60T 5.08 Cm Hydraulic Cylinder Jack Hollow Single Acting Hydraulic Ram Cylinder 50 mm Hydraulic Lifting Cylinders for Riggers Fabricators (60T 2 Inch Hollow)
(5)
418.9
458.99
Deal after registering
Member discounted price
0% cash back
at checkout.
418.9
Non-PRO Account
418.9
Save
Non-PRO Account
Out of Stock
Notify Me
Registered
VEVOR 10 Ton Porta Power Kit, Hydraulic Ram with Pump, Car Jack with 1.4 m Oil Hose, Bent Frame Repair Tool with Storage Case for Automotive, Garage, Heavy Equipment, Mechanic
(77)
241.9
245.99
Deal after registering
Member discounted price
0% cash back
at checkout.
241.9
Non-PRO Account
241.9
Save
Non-PRO Account
Out of Stock
Notify Me
Registered
Quick look
VEVOR Farm Jack, 91.5 cm Utility High Lift Farm Jack, 3.18 Ton Capacity Ratcheting Off Road Utility Jacks, Heavy-Duty Lift Jacks with 130.1-769.6 mm Lifting Range for Tractor, Truck, SUV
(3)
87.9
115.99
Deal after registering
Member discounted price
0% cash back
at checkout.
87.9
Non-PRO Account
87.9
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR Farm Jack, 845mm Utility High Lift Farm Jack, 3.18 Ton Capacity Ratcheting Off Road Utility Jacks, Heavy-Duty Lift Jacks with 130.1-711.2 mm Lifting Range for Tractor, Truck, SUV
(3)
85.9
77.99
Deal after registering
Member discounted price
0% cash back
at checkout.
85.9
Non-PRO Account
85.9
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR Underhoist Support Stand, 3/4 Ton Capacity Under Hoist Jack Stand, Lifting from 1372 to 2130 mm, Bearing Mounted Spin Handle, Self-Locking Threaded Screw, Stable Base, Support Vehicle Components
82.9
74.99
Deal after registering
Member discounted price
0% cash back
at checkout.
82.9
Non-PRO Account
82.9
Save
Non-PRO Account
Out of Stock
Notify Me
Registered
Quick look
VEVOR Farm Jack, 122 cm Utility High Lift Farm Jack, 3.18 Ton Capacity Ratcheting Off Road Utility Jacks, Heavy-Duty Lift Jacks with 130.1-1079.5 mm Lifting Range for Tractor, Truck, SUV
(3)
144.9
168.99
Deal after registering
Member discounted price
0% cash back
at checkout.
144.9
Non-PRO Account
144.9
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR Trailer Jack, 2267 kg Dynamic Load Capacity, Heavy Duty Swivel Bolt-on Trailer Jack, 365 mm Lift Trailer Jack Stand with Handle for RV Trailer, Horse Trailer, Utility Trailer, and Yacht Trailer
102.9
97.99
Deal after registering
Member discounted price
0% cash back
at checkout.
102.9
Non-PRO Account
102.9
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR Farm Jack, 107.5 cm Utility High Lift Farm Jack, 3.18 Ton Capacity Ratcheting Off Road Utility Jacks, Heavy-Duty Lift Jacks with 130.1-929.6 mm Lifting Range for Tractor, Truck, SUV
(3)
130.9
133.99
Deal after registering
Member discounted price
0% cash back
at checkout.
130.9
Non-PRO Account
130.9
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR Low Profile Floor Jack, 2.5 Ton Capacity, Aluminum & Steel Racing Floor Jack with Dual Pistons Quick Lift Pump, Hydraulic Trolley Car Lift for Sedans & Compact SUVs, Lifting Range 95-475 mm
298.9
305.99
Deal after registering
Member discounted price
0% cash back
at checkout.
298.9
Non-PRO Account
298.9
Save
Non-PRO Account
Out of Stock
Notify Me
Registered
Quick look
VEVOR Underhoist Support Stand, 3/4 Ton Capacity Under Hoist Jack Stand with Two Wheels, Lifting from 1320 to 2032 mm, Bearing Mounted Spin Handle, Foot Pedal, Stable Base, Support Vehicle Components
100.9
94.99
Deal after registering
Member discounted price
0% cash back
at checkout.
100.9
Non-PRO Account
100.9
Save
Non-PRO Account
Out of Stock
Notify Me
Registered
Quick look
VEVOR 20T/44000LBS Hollow Hydraulic Cylinder Jack 100mm Plunger Ram Hydraulic Solid Cylinder Hydraulic Jack for Car/Van/Boat/Truck/Caravan
(5)
193.9
205.99
Deal after registering
Member discounted price
0% cash back
at checkout.
193.9
Non-PRO Account
193.9
Save
Non-PRO Account
Out of Stock
Notify Me
Registered
Quick look
VEVOR Under Hoist Tripod Stand, 2 Ton Capacity High Lift Jack Stand Reach Underhoist Support, Lifting from 1200 mm to 2150 mm, 4-Level Adjustable Height, Heavy Duty Carbon Steel for Car Lift & Support
113.9
133.99
Deal after registering
Member discounted price
0% cash back
at checkout.
113.9
Non-PRO Account
113.9
Save
Non-PRO Account
Out of Stock
Notify Me
Registered
Quick look
VEVOR Hydraulic Cylinder Jack 50T 150 mm Stroke Single Acting Hydraulic Cylinder Jack Ram
(3)
270.9
298.99
Deal after registering
Member discounted price
0% cash back
at checkout.
270.9
Non-PRO Account
270.9
Save
Non-PRO Account
Out of Stock
Notify Me
Registered
Quick look
VEVOR Ratcheting Wheel Dolly 1360 kg Auto Truck Vehicle Moving Lift Jack 2 Pack
(31)
363.9
352.99
Deal after registering
Member discounted price
0% cash back
at checkout.
363.9
Non-PRO Account
363.9
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR Stunt Scooter, Complete Trick Scooters for Kids Ages 11-13 Years, Teens, Adults, Boys, and Girls, Freestyle Street Rider for Intermediate and Beginner, Lightweight Aluminum Deck, ABEC-9 Bearing
(4)
103.9
118.99
Deal after registering
Member discounted price
0% cash back
at checkout.
103.9
Non-PRO Account
103.9
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR Poker Chip Set, 300-Piece Poker Set, Complete Poker Playing Game Set with Aluminum Carrying Case, 11.5 Gram Casino Chips, Cards, Buttons and Dices, for Texas Hold'em, Blackjack, Gambling
(1)
48.9
57.99
Deal after registering
Member discounted price
0% cash back
at checkout.
48.9
Non-PRO Account
48.9
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR Poker Chip Set, 300-Piece Poker Set, Complete Poker Playing Game Set with Carrying Case, Heavyweight 14 Gram Casino Clay Chips, Cards, Buttons and Dices, for Texas Hold'em, Blackjack, Gambling
(1)
99.99
114.99
Deal after registering
Member discounted price
0% cash back
at checkout.
99.99
Non-PRO Account
99.99
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR Hand Chain Hoist, 2200 lbs /1 Ton Capacity Chain Block, 20ft/6m Lift Manual Hand Chain Block, Manual Hoist with Industrial-Grade Steel Construction for Lifting Good in Transport & Workshop, Yell
(25)
93.9
94.99
Deal after registering
Member discounted price
0% cash back
at checkout.
93.9
Non-PRO Account
93.9
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR Hand Chain Hoist, 2200 lbs /1 Ton Capacity Chain Block, 15ft/4.5m Lift Manual Hand Chain Block, Manual Hoist with Industrial-Grade Steel Construction for Lifting Good in Transport & Workshop, Ye
(25)
75.99
90.99
Deal after registering
Member discounted price
0% cash back
at checkout.
75.99
Non-PRO Account
75.99
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR Chain Hoist Chain Block 2 Ton Capacity 2.5 M Lift Steel Construction Red
(25)
67.9
90.99
Deal after registering
Member discounted price
0% cash back
at checkout.
67.9
Non-PRO Account
67.9
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR 1 Ton Hand Chain Hoist, 2200 lbs Capacity Chain Block, 10ft/3m Lift Manual Hand Chain Block, Manual Hoist with Industrial-Grade Steel Construction for Lifting Good in Transport & Workshop, Red
(25)
67.9
75.99
Deal after registering
Member discounted price
0% cash back
at checkout.
67.9
Non-PRO Account
67.9
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR Chain Hoist Chain Block 2 Ton Capacity 2 M Lift Steel Construction Red
(25)
54.9
93.99
Deal after registering
Member discounted price
0% cash back
at checkout.
54.9
Non-PRO Account
54.9
Save
Non-PRO Account
Out of Stock
View Details
Quick look
VEVOR Hand Chain Hoist, 2200 lbs /1 Ton Capacity Chain Block, 10ft/3m Lift Manual Hand Chain Block, Manual Hoist with Industrial-Grade Steel Construction for Lifting Good in Transport & Workshop, Blac
(25)
45.9
86.99
Deal after registering
Member discounted price
0% cash back
at checkout.
45.9
Non-PRO Account
45.9
Save
Non-PRO Account
Out of Stock
View Details
Related searches
jacking lift
hi-lift jack
lifting lift
come along for lifting
jacks and lifts
lifting jacks
lift jacks
lifting
See more
VEVOR 4 Ton Porta Power Kit, Portable Hydraulic Jack with 3.9 ft/1.2 m Oil Hose, Auto Body Frame Repair Kit with Storage Case for Car Repair, Truck, Farm (8800 LBS)
(77)
152.9
0% cash back
at checkout.
152.9
152.9
152.9
PRO Savings:
In Stock.
Add to Cart
1
You May Also Like
Today's Deals For You
Recently Viewed
Tips & Inspiration
Recommended Searches
all hydraulics
ton hydraulic jack
one ton hydraulic jack
hydraulics hydraulics
patient slings for lifts
use of hydraulic jack
old hydraulic jack
hydraulics inc
a hydraulic
hydraulic jacks
best hydraulic jacks
hydraulics
hydraulic jack near me
hydraulics near me
jacks for cars
different jacks for cars
car jack in car
car on jacks
a car jack
in car jack