This is a replacement 54T (0.8 Metric Pitch) spur gear from Traxxas. This gear mounts to the input shaft of the transmission, and meshes with the pinion gear on the clutch bell. Traxxas 54 tooth spur gear is constructed of nylon and black in color with a .8 Module pitch. Includes: One 54T 0.8 Pitch Spur Gear