Meccanixity Pneumatic Tubing Pipe, 4Mmx2.5Mm 525Ft 160 Meters Pu Air Line Tubing The pneumatic tubing pipe is made of PU materials, with high elasticity and flexibility. Suitable for air, water, lubricants, instrument lines, irrigation control systems, textile mills, ship fuel delivery pipes, vacuum systems, air conditioning systems, hydraulic brake systems, and other industries. Length: 160 meters / 525 feet; Outer Diameter: 4mm / 0.16 inch; Inner Diameter: 2.5mm / 0.1 inch. PU tube pipe is designed with excellent flexibility and multiple folds without traces, made of polyurethane with a smooth inner wall, low coefficient of friction, and smooth flow of air or fluid. The flexible tubes can be bent in various shapes without other tools and can keep stable sizes with low permeability. All the sizes are manual measurements, most carbon fiber tubes will have an error of +/- 0.1 inch.