TS16949:2009, ISO9001:2000, DOT certificate Double layer nylon tube reinforced tube :1).Material: PA, Nylon ... ; widely use for automobiles,machines.etc.7). Single tube,double tube------------------------------------------------NicholeMob.: +86- 159 2581 6050Tel: +86-0575 ... brake reinforced hose, air brake coil with double layerDouble tubing--Double layer nylon tube,double braided tube,reinforced tube