The MotorVac TransTech III's advanced electronic interface allows complete, "one touch" control. This system offers a quick and easy "drain pan" function for transmission filter changes during ATF exchange. TransTech III connects through transmission cooler lines and provides a clean, "environmentally friendly" and systematic approach to servicing automatic transmissions. The unit will flush virtually all of the old transmission fluid and replace it with the new fluid while the engine is running. By allowing the vehicle's transmission pump to flush out the old fluid while the TransTech III system pumps in new fluid, virtually all of the old fluid can be replaced. The TransTech III completes the fluid exchange faster and more efficiently because of its unique interface and easy-to-use design.