The Simple Pendulum Physics Experiment Kit
by Science Supply Solutions

Brightly colored, this pair of pulleys features both a single and double tandem pulley that can be added to almost any one of your experiments to increase the difficulty. Made of a durable, lightweight plastic, each one has a diameter of 50mm. The pulley blocks themselves are held in place by a chrome-plated metal frame. Also included in the kit is some string to use with the pulleys, and an illustrated activity guide.

Designed to support movement and aide in the changing of directions, as well as the lifting/lowering of loads, and for the application of forces. It typically has a groove that runs between a pair of flanges around its circumference. As the number of pulleys increases, the amount of work required to lift or move the object at the other end can be decreased.