Kyosho Inferno Steel Ring and Pinion Gear Set is used on the Inferno GT2 and Inferno VE. Made of high grade steel they are durable and use a helical cut for more meshing surface. Includes 1 pinion gear, 1 ring gear and a shim. Take care when installing Ring and Pinion Gears, they must be shimmed correctly.Make sure you run them with zero backlash for a few tanks, then check them. There should be close to zero backlash even after this. Check them regularly and re-shim if necessary.