... , DOT certificate Air brake coil with double layer nylon :• Material:PA,PU,double nylon tube• Hose size(OD*ID):12×9,12 ... ,80,70,60,50mm etc.• Helix turns/coil:12,16,18,20,22,24,26,28,30 coils.etc.• Stretched length ... you're also interested inTube -- PA (Polyamide, Nylon) Coil Tube, spiral hoseTubing -- PA (Polyamide, Nylon) TubeTube-- PU (Polyurethane) TubeTubing -- PU (Polyurethane) air ...