... the delivery of refrigerants R12,R22,R502,andR134a with fittings sets .500psi/2500psi or 600psi/300psi.Good quality Freon Charging hose is 1.Widely used in ... .The inner layer consisted of a special rubber of R12,R22,R134 ,and R502 resistance.3.The outer layer is consisted of rubber with ... Brass nuts or Iron nuts,as our customer's required Freon charging hose