The Northwest Instruments NRL802 Self-Leveling Rotary Laser 90106 is equipped with performance tilt sensors and servo motors that provide accurate leveling in both horizontal and vertical directions within 5 degrees. It offers a continuous 360-degree horizontal coverage, two rotation speeds, manual slope matching, and 5/8 x 11-inch tripod thread. Capability The NRL802 has robust construction that makes it ready for the job site as well as resistant to dust and water. It has indoor features including a wide sweep, narrow sweep and dual beam squaring for both level and plumb. A convenient bump sensor alerts you if the laser is bumped out of place, protecting against inaccurate aim. Accuracy The NRL802 rotary laser offers an operating range up to 2,000 feet radius when used with the optional NLD5G laser detector. Its horizontal accuracy is 1/16 inches at 100 feet and it has a vertical accuracy of 1/8 inches at 100 feet. There is an out-of-range alarm,