Johnson Level and Tool 40-6515 Self-Leveling Rotary Laser Level Locking mechanism protects inner pendulum during transportation Self-leveling in the horizontal plane Manual-leveling in the vertical plane with 90 split beam with illuminated vertical vial Visual and audible alarms when beyond leveling range Laser rotates at 200, 400, 600 RPM Laser Class Illa, &lt;5mW Laser Class llla Power output Less/Equal to l/M/5M Laser Class Illa, &lt;5mW