Easy steps:
step 1: position and place unit against wall adjust until bubble is level.
Step 2: turn on depress on/off button to shoot a perfectly straight laser line.
Usage:
hanging pictures
building a level wail
aligning shelves
perfecting aligning
decorating your home
Wave length: 650nm
Laser power: ≤3mw
Level vial accuracy: 30'/2mm
Beam level accuracy: ±1. 5mm/3m
Voltage: 3v