... pulley:1. Plain bore: MXL, XL, L, H; T2.5, T5, T10; AT5, AT10; HTD 3M, 5M, 8M, 14M.2. Taper ... Treatment: Black, Phosphate, Zinc Plating, Hard anodized, Nitriding, Dichromate.5. Teeth Number is from 9 to 216.Specifications1.high quality and ... good qualityCertification:We've been ISO9001:2000 certified since 2003. T5 timing pulleys