Hot Racing 54 tooth hardened steel Modulus 1 (1.0 metric pitch) spur gear for the Traxxas E Revo2, X-Maxx 6S and 8S, and XO-1.FEATURES: - CNC machined hardened steel construction- Black oxide finished- Laser etched tooth count markingYOU WILL RECEIVE: - One (1) 54 tooth, 1.0 modulus steel spur gearREQUIREMENTS: - Do NOT use the pin system for setting the X-Maxx gear mesh. Instead, manually set the gear mesh without the pins. Refer to the Traxxas manual for instructions (ref. pg.22 - Adjusting Gear Mesh): - With the pins removed, use the four 4x16mm button-head cap screws on the bottom to set gear mesh. Loosen the four 4x16mm button-head cap screws. Cut a narrow strip of notebook paper and run it into the gear mesh. Slide the motor and pinion gear into the spur gear. Tighten the four 4x16mm buttonhead cap screws, and then remove the strip of paper. You should be able to run a fresh strip of paper through the gears without binding them. SPECIFICATIONS: - Overall diameter: 56.8mm- Gear face width: 8mmCOMMENTS: - Replaces Traxxas plastic 6449 or 6449X 54T spur gear