... 3/4, (2) Length:3,4,6,7,10m insulation tube of air conditioner&air conditioner pipeTwin/pair insulated(isolated) copper ... the CE certificate and pass the SGS test!1,Copper tube:O.D.1/4''&3/8'',1/4''&1/2 ... 3/8''&3/4'',1/2''&3/4''2,Copper tube:thickness from 0.5mm to 1.5mm.3,Length: ... complied: GB/17791--1999,JISH3300,ASTM B7435,Thickness of copper tube compatible any gases:R22,R407C,R410A,R404A,R507C etc.6 ...