Image Item No. Description  wheel1b  Train Wheel with 2 x 2 Stud Center, Beveled Tread and Cam Axle for Motor Catalog: Parts: Wheel  wheel1a  Train Wheel with 2 x 2 Stud Center, Traction Teeth Catalog: Parts: Wheel  7039b  Wheel with 4 Studs and Axle Cam for Motor Catalog: Parts: Wheel  715a  Wheel with 12 Studs and Axle Cam for Motor Catalog: Parts: Wheel