Specifications:Material: AluminumBore: 5mmFeatures:1.Designed with double flange, admits synchronizing shaft rotations.2.It is very useful in high-reduction drives in the occasion that need to improve the wrap-around capabilities of belts.3.Used widely in milling machine, 3D printer, drilling machine or other machinery transmission.Package Includes:1 X 3 M 5mm Bore Timing Pulley