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 The 3bar MAP sensor is needed to avoid limp mode when using the stage2 map. NOTE: Use 1.65bar with caution - its strongly recommended turbo being in perfect condition. Clutch wear If using 2256 its preferred no full throttle for extended periods such as top speed on highways.