The Wheel and Axle is used to show the relationship and significance of various pulley diameters when used in a mechanical system. This aparatus consists of a molded wheel with four individual pulleys of different diameters. The ratios of these diameters is a sequence of approximately 3, 2, 1.5, and 1. 

There are small holes drilled in each rim for attaching your pulley string. The ball bearing and stainless steel axle assure low friction and better results.  The 13cm axle can be be attached to a stand using a normal bosshead clamp