Timing pulleys (XL,L,H,XH,XXH) HTD Timing pulleys(3M,5M,8M,14M, ... ,T20,AT5,AT10),etc. timing pulley HTD ,Timing pulleys (XL,L,H,XH,XXH) HTD Timing pulleys(3M,5M,8M,14M ... (T2.5,T5,T10,T20,AT5,AT10),BTL Timing pulleys(L,H,XH)The surface treatment of timing belt pulleys is ... :black oxide,phosphate,anodize and zinc plating. Timing pulleys (XL,L,H,XH,XXH)