These 1/5 inch Pitch (XL) Pulleys are precision molded to match belt configuration and provide accurate register between drive and driven shafts. They are molded of fiberglass-reinforced nylon for light weight, exceptional strength and quiet running characteristics. All hubs are drilled, tapped and supplied with stainless steel set screw. For certainty of attachment, pulleys can be cross drilled and fixed with a bolt or dowel pin.