1 supply shell and chain 2 material: A3\C45 and customer requirement 3 high precision transmission coupling 4 CNC Tech Products Featuresprocket coupling 1, all made by advanced CNC lathe, pass ISO, ANSI quality certification. high precision and good wear resistance. 2, surface treatment is black, galvanization, chroming and colored drawing. 3, material is A3\C45, stainless steel and customer ...