The page states the size"Inner diameter: 1/8" (3mm). Outer Diameter: 9mm Length: 5 feet (60 inches). Wall thickness: 3 mm. "However, the actual outside diameter is about 7.9 mm, which is far too small for my application. I specifically needed the 9mm size to fit the special steel clamps I ordered for the turbo exhaust valve application. Return and purchase from another supplier. Hopefully UPGR8 will pick up its moves and list correctly sized items.