Metallic Pulley - 4mm bore diameter
A pulley is a wheel on an axle or shaft that is designed to support movement of a cable or belt along its circumference. Pulleys are used in a variety of ways to lift loads, apply forces, and to transmit power.
Overall outer diameter : 1" or 2.54 cm
Groove/Belt/Chain diameter : ~2.2 cm
Bore/ Shaft Diameter : 4mm (In case if DC motor has 6mm dia shaft it can be converted to 4mm by 6mm to 4mm shaft dia converter)