Backtrack 2 True Dual Tire Truer w/Ball Bearings: The 2022 Version w/ball bearings and built in micrometer measuring system, no more bolts required to set and repeat sizes! Dual drums allow truing a pair of tires at the same time. Uses 1-1/2" drums available at your local hardware store to allow different grits of paper. Powerful 110 V AC Motor does not require an external power supply to operate. Axle included is for 3/32" Wheels and can be switched out with any 1/8" Axle for 1/8" wheels. A 2mm option will be available soon for faster scale cars. Has enough clearance to true 1-5/16" drag tires.