stainless steel pipe: use for solar energy recirculation pipe, have many size:1/2"3/4".., high quality sus 304-2B,food-level, wave pipe have many size, material: sus304-2B, use for recirculating pipe, durable, also can supply the tools, like pipe cutter, and end maker! size: diameter: 16mm,19mm, length: 20m/roll.