This is a bottle of Mercedes-Benz genuine automatic transmission fluid (ATF). It is a Dual Clutch Transmission (DCT) fluid with Mercedes-Benz specification MB 236.21. The fluid is designed for specific Mercedes-Benz transmissions, such as the 7G-Tronic Plus, and is not backward compatible with all earlier specifications. It comes in a 1-liter bottle. The fluid is formulated to optimize efficiency and provide superior low-temperature performance. Disclaimer: Always consult your vehicle's owner's manual to ensure this fluid meets the exact specifications required for your specific transmission model.