Make of thick purpleness Coppers,resistance,leakage,fractures. nut have high hardness,slipping,Enduring.Mechanical precise reaming,burr,leakage,more secure to use. Adopting double layer thermal insulation cotton,which have the characteristics of heat insulation,shock absorption and not easy to age. Assembling this is quick and easy.Hose the lowly and highly pressure tubes together without manual welding. Specifically for small split air conditioning systems.Suitable for shopping,offices,homes,restaurants,ensuring efficient refrigeration.