The Flywheel Accessory is attached to the Generator (ET-8771) See photo below left, to demonstrate the storage of rotational kinetic energy. The solid aluminum disk (6.3 cm
diameter, 80 g mass) keys into the shaft of the Generator to prevent slipping. A thread attached to a hanging weight easily wraps around the built-in pulley.

ET-8773 Flywheel Accessory has a built-in pulley and a spiral pattern on the label to show rotational motion.