Time-Saving Quick Clamp Design: Push the teeth clamp lever to quickly move the wing nut onto the shaft without having to screw it all the way on when balancing wheels Critical Measurement Required: You must check the shaft thread pitch to see if you have a 3mm or 4mm before ordering to ensure proper fit Thread Pitch Measurement Guide: When measuring the shaft, the thread pitch would be approximately 7 threads per inch for proper identification Wide Compatibility with Major Brands: Fits all of the following (NON Road Force) wheel balancer models with a 40mm X 4mm thread pitch shaft: Accuturn: 1200, 1220, 1250, 1400, 1420, 1450, 1500, 1520, 1550, 1650, 1820 & 1850, Bosch: All Models, Cemb: All models with a 40mm diameter shaft, 1995 & later, Coats: All XR balancers, FMC / John Bean: All Models with a 40mm shaft, Kwik Way: 402, 571, HS, 572, 574, 576, 578, Launch: 408, 500, SNAP-ON: All models with 40mm shaft Complete Kit Contents: Kit includes Quick Clamp Wing Nut, Pressure Cup, Protector Ring, and Nut Bearing for comprehensive wheel balancing functionality Will fit all model balancers with 40mm X 4mm shaft. To check, measure the shaft diameter (40mm) and the thread spacing (4mm) on your balancer shaft. Thread spacing is the distance of one thread and one space; for example, the distance from the left edge of a thread to the left edge of the next thread (Approximately 7 threads per inch).