Features Complete Set: Includes four synchronous wheels, two belts, and one hex wrench, providing all necessary components for practical use. Durable Aluminum Alloy: The synchronous wheel is constructed from high hardness aluminum alloy with oxidized finish, ensuring fine workmanship and high transmission accuracy. Long-lasting Rubber Belt: Made of durable and elastic rubber material, the belt offers a long service life, contributing to a reliable and unparalleled user experience. Efficient Energy Saving: Easy to install and disassemble, the set provides stable transmission, accurate tooth pitch, high transmission efficiency, and excellent energy-saving effects. Versatile Application: The synchronous wheel set is suitable for various mechanical transmission situations, including 3D printers, milling machines, drilling machines, and CNC lathes. Specification: Item Type: Synchronous Wheel Set Material: Aluminum alloy, rubber Timing Belt Length: Approx. 400mm/15.75in Timing Belt Width: Approx. 6mm/0.24in Teeth: 20T and 60T Screw: M4 Package List: 4 x Synchronous Wheel 2 x Belt 1 x Hex Wrench Package List 4 x Synchronous Wheel 2 x Belt 1 x Hex Wrench