... , DOT certificate Air brake coil with double layer nylon :• Material:PA,PU,double nylon tube• Hose size(OD*ID ... 12,16,18,20,22,24,26,28,30 coils.etc.• Stretched length:5m,5.5m,6 ... Explosion Pressure :4Mpa(=40Bar) to 10Mpa(=100Bar)• Fitting:With two M16,M18 ,M22 ,1/2"fittings etc. ... reinforced hose, air brake coil with double layerDouble tubing--Double layer nylon tube,double braided tube,reinforced tube