The Pro Shot Alpha laser level features electronic servo self-leveling, allowing users to turn it on and let it level automatically. Other features include 2000-ft-diameter jobsite coverage, 10-arc-second accuracy (1/16 in./100 ft), ±5 degree self-leveling range, manual slope-matching capability, 100-hour battery life (4 C-cell alkaline), and selectable rotation speeds (600/1200 rpm). The tool can withstand a 3-ft drop or 5-ft tripod knock-over onto concrete. Laser Reference Inc. 800-238-0685.