Item Type: 3. 175mm RC Pinion Gear_x000D_Weight: 14g/o. 5oz_x000D_Material: Aluminum alloy_x000D_Modulus: 0. 6M_x000D_Aperture: 3. 175mm/0. 13in_x000D_Number of Teeth: 18T, 19T, 20T, 21T, 22T, 23T (one each)_x000D_Suitable for: for 1/8 1/10 RC climbing car general (e. g. for SCX10, etc. ) 1Applicable Model: 3. 175mm diameter hole allows for easy installation and maintenance. Suitable for 1/8 1/10 climbing remote control car reduction gear set. 2High Grade Material: Aluminum alloy material ensures longer lifespan and increased durability, we offer you better products. 3Reduce Working Noise: Accuracy mechanical machining produces gears with reduced roughness and noise compared to similarly sized gears. 4Provide with 6 Different Gears: Speed depends on gear ratio, and our kit includes six different gear options to provide more choices. 5Ideal Choice: We use strict manufacturing process, M 0. 6 module size makes it compatible with a variety of remote control cars. It's an ideal choice for you.