Designed To Take Up The Gap Between The 26Mm Stud Hole And 22Mm Wheel Stud On Hub Piloted Commercial Wheels. Compatible With Aluminum And Steel. Made From High-Temp Polyamide With Standing Heat Of 450-Degree Fahrenheit Plus! Increase Fuel Mileage, Tire Life, Stop Wheel End Vibration, Stop Irregular Tire Wear, Decrease Maintenance, Reduce Tire Cupping Re-Aligns The Wheel To The True Center Of The Hub Bearing. Available In 20Mm Or 22Mm.Comes In 6Pk, 100Pk, And 1000Pk + Free Installation Tool.