Metric sizes are from 3x2 to 16x12, optional inch size from 5/32" to 1/2". The polyurethane tubing (PU tube) normally has blue, black, orange 3 color, there're other sizes like yellow, green, red, etc. For optional.

Polyurethane tubing is widely used in the pneumatic system to transfer the pressure air power, Without polyurethane tubing (PU tube), the pneumatic system can't fit together. XCPC pneumatics & hydraulics provides polyurethane tubing (PU tube) in very good quality, precise, flexible, smooth, nice apperance, a very good solution for a complete pneumatic system.