The Studica Robotics HEX Chain and Sprocket Pack is a complete power transmission hardware kit built for competitive robotics, classroom projects, and custom mechanical designs. This comprehensive pack includes a heavy-duty #25 roller chain with master links, a variety of precision sprockets, flanged bearings, shaft hubs, spacers, collars, socket head cap screws, and a chain breaker tool — giving you everything needed to build efficient drivetrain systems or other mechanical linkages.