ITEM NAME:Steel Main Gears Spur Differential Motor Cogs for HSP HPI Redcat RC Truck Description: - 64T main gear and 17T 21T 26T 29T motor gears combo - Made of high quality material - Durable metal construction for long-lasting performance - Rust-proof treatment on the surface of gears - Suitable for HSP, Redcat, HPI 1/10 rc car - Material: 11184 Steel Size Chart: Height: 11mm (motor gear); 9mm (main gear) Tip diameter 17T: 11.5mm 21T: 14mm 26T: 16.5mm 29T: 18.5mm 64T: 40mm Suitable shaft diameter: 3.175mm (motor gear); 5mm (main gear) Package Included: 1 Piece 17T Gear 1 Piece 21T Gear 1 Piece 26T Gear 1 Piece 29T Gear 1 Piece 64T Gear.Suitable for HSP, Redcat, HPI 1/10 rc car. - 64T main gear and 17T 21T 26T 29T motor gears combo. Height: 11mm (motor gear); 9mm (main gear). - Material: 11184 Steel. 29T: 18.5mm.