... TS16949:2009, ISO9001:2000, DOT certificate Double layer nylon tube reinforced tube :1).Material: PA, Nylon ,Polyamide2).Size: O ... )4×2125,50,100,2005×31 6×41 8×61 10×81 10×7.51.25 10×71 ... 5 15×121.5 Inch: 1/4”,3/8”, 1/2”,5/8” etc.3). Working temperature: -40~+120°C ... PU (Polyurethane) air brake coilsDouble tube--Trailer air brake reinforced hose, air brake coil with double layerDouble tubing--Double layer ...