Dual-map unit. You switch between maps/tunes via switch directly while driving. No need to turn off engine. Most usable combo is ECO map for long trips + Power tune. NOTE: If you are choosing the 1.65bar map you do need to order the 3bar map sensor if you don't have one. Link for purchasing https://www.ecuwire.com/store/3bar-map-sensor-fae-15028 Contact for any questions.