Timing pulleys aluminum material and Bs TYPE PULLEYS ISO9000:2008 Plain surface treatment or brighten Competitive prices Timing pulleysAluminum material or iron casting material pulleysStandard specificationISO9001:2008Timing pulleysArc or T type teeth.MXL, XL, L, H, T,XXH, XH, AT typesynchronous pulleys Timing pulleys