The Nitecore SENS AA2 features the innovative ADT mode (active dimming technology) which is an integrated acceleration sensor and micro processor which work together to calculate the distance of targets based on geometric theory. The sensor continuously detects the angle of the flashlight in relation to floor, while the micro processor uses this data to vary the light output. For example, turning the SENS AA flashlight on with the head pointed straight up activates active dimming mode. When held in a horizontal position, output will seamlessly and automatically increase for the illuminating targets at a distance. When held vertically, output will seamlessly and automatically reduce for closer range targets. When in ADT mode, you can enjoy significantly longer runtimes.