➜One 129 mm diameter Drive wheel CNC machined with 19 mm bore and 6 mm Keyway ➜Two x 51 mm diameter Idler Wheels: Each wheel is fitted with three 12 mm bearings ➜One 102 mm diameter Track Wheel: Each wheel is fitted with three 12 mm bearings ➜Manufactured Using State of the Art CNC machines ➜A 70 mm long M12 bolt (can be all or partly threaded) Should be used to fit idler and tracking wheels - No Bolts included-, Weight: 4.850169764 pounds, Manufacturer: Smart Machines