Within the Rolling Elements & Wheels subcategory of Power Transmission, Pulleys are key components used to transmit mechanical power across machinery via belt drives. These wheel-like devices feature grooves along their edges to guide and hold belts, allowing for efficient power transfer from one rotating shaft to another. Pulleys are essential in systems where changes in speed and power output are necessary, such as in conveyors, lifts, and various types of industrial machinery. They are crucial for managing rotational speed, increasing torque, and directing power effectively within mechanical systems.