I purchased the 100W 1430mm tube and matching power supply. It arrived well packaged, undamaged, and quickly from a US shipping location. It wasn't clear from the description if the 100W tube has the same features as the 130w version. The 100W does have all the features. The German made tube, the metal end, the attached power leads, and the 2.5mm beam size.The metal end makes aligning the tube easier as the face is perpendicular to the beam. My original tube has a glass end that was curved from the glass blowing process. Not a defect, just made using it as a reference point impossible.The attached power leads meant that the connection to the tube was clean and secure. The extreme high voltage of these connections means they are prone to arcing. This is dangerous and can dramatically shorten your tube life.The most important part to me is the 2.5 mm beam size. As the power increases with CO2 laser tubes, the width of the unfocused beam increases. My original 60W tube had a 5mm beam and typical 100W tubes have between an 8 and 10 mm raw beam. Since the mirrors are at a 45 degree angle a 25mm mirror has a target width of around 17mm. A 10mm beam has to be very accurately aimed to make it to the laser head. This has to be done 3 times. A 2.5mm beam has much more room to hit the mirror. Where the beam hits the mirror doesn't matter because it is the beam's deviation from the axis of travel that matters. If it isn't parallel to the axis, then the point where it hits the mirror changes as the laser moves. This means that the point where it hits the second mirror changes as well. This magnifies the error and the beam will eventually hit the focussing lens in different places. At best this just varies the cutting power by changing the focus point. At worst it sends the beam into the side of the nozzle and it reflects to a different cutting path. This means ghost lines or just scorching the item you are trying to cut.The other benefit to the 2.5mm beam is that it will make a tighter focused beam when it hits the stock you are trying to cut. This means a narrower kerf to the cut. This is more important to engraving than cutting because it changes the size of the dot in the image. The smaller the dot, the crisper the engraving. Smaller dots with the increased power means engraved images can be produced significantly faster.
john davis 
