AC hose 1.DN:6-19 2.Material:NR 3.Innter ... : rubber endure R134a 4.Mainly used in air conditioning system AC hoseUsed in air conditioners of autos. Classified into F-134a ... against permeation of cold media, oil, ozone, and heat. Low noise, good flexibility, stable tolerance, good assembly. Used in -30--120 ... : 5/16" , 13/32" , 1/2" , 5/8" , 3/4" AC hose