High performance chain wheel with improved torsion spring. The chain sprocket fits for many 110cc 125cc 140cc Dirt Trail Bike, Quad, Mini Moto, ATV. Premium quality aftermarket replacement chain roller tensioner. Spring loaded tensioner automatically adjusts tension to chain length. Smooth rotor rotation and longer service life. Easy to install. Note: The data are all measured manually, please allow 1-3cm error due to different light and display, there may be some color differences, please refer to the actual item received.