fittings (press fitting and screw fitting) specially fit our pipes, related to plumbing system. Raw materiel: main body is copper, can be nickled as your wish Demensions: 1)Easy installation:separated structure makes it very convenient for installation and dismounting. 2)Additonal sealing: apart from the metal-to- metal seal, there is an additional O-ring seal between the taper of the insert and the fitting body. 3)Corrosion insulation: a thin gasket on the insert serves as an insulation ring, preventing the bimetallic corrosion between the insert and the aluminum core of the compposition pipe. 4)Flexibility: a fitting body can share different inserts, which have the same taper part but different inner diameters. We also supply: 1)Male Union, Female Union , Equal Sraight Union , Unequal Straight Union. 2)Equal Tee, Unequal Tee , Female Tee , Wall-planted Femal Tee 3)Female Elbow , Male Elbow , Equal Elbow Please contact us if you need it . Thank you!