Odstore Professional Red Automatic Self Leveling 5 Line 6 Point 4V1H Laser Level Measure LomVum Waterproof Laser Level Automatic self leveling mechanism. Audio warning when beyond auto leveling range.Automatic leveling in the range of 3 Adjust feet,360 rotating base with fine tuning knobPower:AC 110-240v / 3 x 1.5V AA Dry Battery( Does not include battery), 5 laser lines (4 vertical and 1 horizontal),6 points Working distance:. Indoor working radius of about 15m , outdoor 10m (without Receiver). When using an outdoor receiver operating radius about 70m. Continuous working time: about 20 hours by Battery, or long time by AV Power