Hot Racing CSG1213 13t 32p Hardened Steel Pinion Gear 1/8 Bore Made by Hot Racing; Hot Racing is a United States based company; parts are sourced from Chinese producers All Hot Racing upgrade parts are direct replacements for stock components; additional parts are not required Hot Racing part number CSG1213; UPC 083745605990 This item works with: Associated RC-10 original aluminum chassis; Tamiya Clodbuster and Super Clodbuster; Traxxas E-Maxx, E-Revo 5603 5605 5608, Slash 4x4 all versions