Royal Purple Synchromax is a manual transmission fluid that increases performance and the life of your equipment. It improves shifting, reduces gear noise and increases power transfer to the wheels. It also lowers operating temperatures and provides outstanding wear protection for longer transmission life. 1 quart bottle. Synchromax is recommended for manual transmissions that specify an automatic transmission fluid. It’s also ideal for 4×4 transfer cases and motorcycle gear boxes. Synchromax is fully compatible with all types of friction materials. It provides excellent corrosion and oxidation protection without affecting the soft metals commonly found in manual transmission synchronizers. Synchromax is formulated with Royal Purple’s proprietary Synerlec technology for unsurpassed performance and protection.