Hot Racing CSG1831 31t 48p 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 CSG1831; UPC 083745713251 This item works with: Associated RC-10 B4.x, SC-10 2WD; Axial Wraith 4WD Rock Racer RTR; Losi 1:10 Strike, 1:10 TLR 22 2WD Buggy; Traxxas 1/16 E-Revo VXL, Rustler VXL Velineon Brushless, Rustler XL-5, Slash 2WD all versions, Stampede Electric, Stampede VXL, Stampede XL-5