From the Manufacturer
The LB-10 laser beacon has an invisible beam, is waterproof, two speed head rotation control (5 and 10 RPS), and has two axis leveling in the horizontal plane. With a range of 2000 ft. diameter and an accuracy of 1/16 in. per 100 ft., this self leveling laser is the indoor/outdoor level expert. Complete with laser, charger, NiCad rechargeable battery pack, rod eye-6 sensor, and carrying case.