... , ISO9001:2000, DOT certificate Air brake coil with double layer nylon :• Material:PA,PU,double nylon tube• Hose size(OD*ID):12×9 ... ,70,60,50mm etc.• Helix turns/coil:12,16,18,20,22,24,26,28,30 coils.etc.• Stretched length:5m ... air brake reinforced hose, air brake coil with double layerDouble tubing--Double layer nylon tube,double braided tube,reinforced tube Air brake coil with ...