100% high quality pure copper fittings and Flare Nut Includes 2 Flare Nuts, one pair of connectors, and direct purchase of copper tubes as required Uses: The connection between two copper pipes, one to two, quick connection, no welding, can be tightened with a wrench. Air-conditioning copper pipe joints, 6-19MM double joints, intermediate joints, high-quality copper cores are sturdy and durable, and are not easily damaged when installed. The joint is used to lengthen the copper tube, it can be used when bought back, no welding is required. Notes: The air conditioning copper tube contains double tubes of different sizes. You need to purchase the corresponding 2 pairs of connectors according to the size of the air conditioner.