Johnson Level and Tool 40-6516 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&deg; split beam with illuminated vertical vial Visual and audible alarms when beyond leveling range Laser Class Illa, &lt;5mW Laser Class llla Power output Less/Equal to 5mW