CAC(copper-aluminum-copper) tube is used to connect the air conditioner's indoor and outdoor unit. Both end of the CAC tube is copper tube, in the middle is Aluminum tube, copper tube and aluminum tube are welded together by a special welding technic. So the cost of CAC tube is much less than the copper tube. Aluminum tube wall thickness is 1.5 times of copper tube, combine our outstanding welding technic, the service life of CAC tube is more than 20 years, it totally reach our standard requirement.