The M12™ Cordless LITHIUM-ION 2-Beam Plumb Laser is the first of its kind to operate on a power tool battery. Powered by M12 REDLITHIUM ™, it is compatible with the M12™ cordless LITHIUM-ION system, and delivers 75% more run-time than the competition. In addition, a self leveling mechanism ensures an accurate auto plumb up to 1/4" at 100 feet, and an out of level indicator blinks when the leveling range exceeds four degrees.