These are optional pinion gears for the Avante and Avante 2001 kits. FEATURES: They are 48 pitch metric 20 tooth and 21 tooth gears. The number of teeth is stamped on the pinion so they cannot be confused which is which. They are made of aluminum. YOU WILL RECEIVE: 1- 48P metric, 20T pinion gear 1- 48P metric, 21T pinion gear 2- set screws WAJ 11/21/93 update btm 07/19/94 &