This is the Traxxas 6491X 18T 1.0 Metric Pinion Gear 5mm Shaft

Traxxas Steel Mod 1.0 Pinion Gear. This durable steel pinion gear has a 5mm bore and a Mod 1 tooth pitch, making it compatible with a variety of applications. The gear is available in a variety of tooth count options, please select the specific gear you want from the pull down list above. Package includes pinion gear and set screw.

Compatibility:

• Traxxas E-Revo VXL 2.0
• Traxxas X-Maxx
• Traxxas XO-1
• Traxxas XRT