Kidders versatile classroom pulley set is designed to teach the mechanical principles of pulleys to a whole class. The set contains 18 single sheave pulleys, 12 doublesheave pulleys, 12 triple sheave pulleys, 6 spring scales (500 g, 50 N), a roll of twine, 20 pulley chain links, and the Pulleys in Motion teacher's guide. This 32-page resource contains background information that gradually introduces students to fundamental pulley concepts, as well as reproducible student activity sheets and assessment ideas. The focus of the Class Set is to provide hands-on activities that are easily understood, and provide both intellectual and practical experience for the students.