Transmission Timing Belt Pulleys Timing belt pulleys. With hub or for taper bushing for easy mounting and dismounting. Metric or inches. Metric HTD Timing Belt Pulleys For pulleys with hub or for pulleys or for taper bored pulleys. Inches XL-L-H Timing Belt Pulleys Timing belt pulleys in inches. Pulley with hub or taper bored pulley. XL: 1/5 inch. L: 3/8 inch. H: 1/2 incl. Metric T / AT Timing Belt Pulleys Timing belt pulleys with hub. Made from aluminum. Poly Chain belt pulleys Gates PolyChain GT timing belt pulleys amde from steel or cast iron. 8M and 14M.