MXL Type Timing Belt Pulley 40 Teeth 6.35mm Bore for Stepper Motor Widely used in machine tools, textile, printing, food packaging, wire and cable, instrumentation, petrochemical, tobacco, telecommunications and other industries in the new mechanical belt drive. Bore Diameter : 6.35mm Number of Tooth : 40;Top screws: M4 Material : Aluminum Weight : 40gPackage Content : 1 x Timing belt pulley