Synthetic technology. Does not contain properties to enhance or modify the system like Penray 6538. Penray 6536 is a great conditioner for ATF. This formula helps reduce micro-pitting on internal gears and components. Use with Penray 6533 Professional Automatic Transmission Flush as part of the Penray 6537 2-Step Transmission Tune-Up Kit: Restores performance, reduces friction and wear and conditions all transmission parts.