Martin timing pulleys are manufactured to extremely close specifications and are stocked in minimum plain bore, taper bushed, QD bushed styles depending on size and pitch. Synchronous sprockets are non-slip toothed drives that require no lubrication. These sprockets have a wide speed range, are very efficient and make less noise than chain drives. Teeth on the belts are molded to conform with and engage the teeth on a mating sprocket. Martin Stock Timing Pulley, Solid Type DF-1, Minimum Plain/Reborable Bore, 0.25 to 0.813 in Bore Dia, 1.508 in Outside Dia, 1.528 in, 24 Grooves, 0.2 in Pitch, 0.563 in Face Width, 1.756 in Flange Dia, 1-1/16 in Hub Dia, 5/16 in Hub Projection, 7/8 in Overall Length, For Use With: Type XL Belt, Steel