This is a new Spur gear (the one that the motor/pinion spins against). It will fit in any 7R gear case (gear case with orange output gear).
IF YOU STRIPPED THIS GEAR THEN YOU'LL WANT TO CLEAN THE GREASE OUT OF YOUR GEARBOX AS IT'S FULL OF NYLON FRAGMENTS. Be sure to pick up one of our Race Grease packets to rebuild your gearcase. One race grease or stock grease packet is enough to do TWO gearboxes.