Duo Tubing Pun-6X1-Duo-Si Standard O.D Tubing, for Qs Plug Connectors, Cn and Ck Polyurethane Fittings (Not Approved for Use In theFood Industry) Outside Diameter=6 Mm, Bending Radius Relevant for Flow Rate=26, 5 Mm, Inside Diameter=4 Mm, Min. Bending Radius=16 Mm, Tubing Characteristics=Suitable for Energy Chains In Applications with High Cycle Rates