I've bought polycarbonate tubing from The Custom Saber Shop, McMaster-Carr, ShadyCanuck of the Imperial Royal Arms forum and from various plastics vendors on the net. They're all legit. There are a few more sabersmiths that sell polycarbonate blades as well. It really depends on what you want in regards to outside diameter, wall-thickness, length, whether or not you want a blade tip and whether or not you want blade diffuser material as to which vendor you choose to do business with.