... 5.Timely Delivery Features:1. Teeth Type: MXL,XL,L,H,XH,XXH,XXL,SL9,SL12,SL,HTD:3M,5M,8M ... ,S5M,S8M,S14M)5. The British System:MXL,XL,L,H,X6. Material:1045 carbon steel, aluminum alloy frequently used,brass ... .7. Surface treatment:black oxdizing,phosphating,anodize,zinc-plating Timing belt pulley