Hot Racing SVX2508 Aluminum Differential Locker Spool - HPI Savage Flex 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 SVX2508; UPC 083745257236 This item works with: HPI Nitro Savage X, Savage X 4.6, Savage XL