The Tamiya Pinion Gear Set 18T/19T is a set of RC Parts. They are 48 pitch metric 18 tooth and 19 tooth gears. The number of teeth is stamped on the pinion so they cannot be confused which is which. They are made of aluminum. Includes One 18T pinion gear (48 Pitch) One 19T pinion gear (48 Pitch) Two Grub Screws Manufacturer: Tamiya Model: 50355 Pinion Gear Set 18T/19T 48 Pitc