For precise motion control, GT2 belts and pulleys offer excellent precision at a great price. This pulley is meant for use with GT2 6mm wide belts only - MXL belts will slip due to the different tooth profile.This pulley has 36 teeth, and a 8mm inner bore. Two set screws can be used to attach it firmly to any 8mm diameter shaft. Full aluminum construction means these are very light and very durable.