Features: Small and light weigh,easy to install and operate. Suit for 1/10 RC Car brushed/brushless motor which shaft is 3.175mm. High quality steel,hard anodized on the gear surface,more durable and wear-resistant. 5Pcs set gives you more choice and make your RC car have best performance. A M3 set screw (12.9 level) has been added to each pinion gear. Specifications: Brand: KingVal Height: 9mm Diametral Pitch: 48DP Suitable shaft diameter: 3.175mm Material: Steel Teeth: 18T 19T 20T 21T 22T Gear size: 18T ?3.175*?10.6*9mm 19T ?3.175*?11.13*9mm 20T ?3.175*?11.66*9mm 21T ?3.175*?12.19*9mm 22T ?3.175*?12.72*9mm Package List: 1 x 18T Gear 1 x 19T Gear 1 x 20T Gear 1 x 21T Gear 1 x 22T Gear 1 x Screw set