Before using, adjust the vial on the tripod frist then adjust levelling screw on the rotary base

to ensure the horizontal vial be centred through acircle of 360°,

at last you can fix your laser lesvel on the rotary base.
There are two knobs on the base, one is to fix the level on the base, the other is to lock the base's rotation.

Max. power output: ²1mW, GS and CE
certified, Class IIIA protection
Wave length: 650Nm
Accuracy: +/-2 mm
Requires Two AA batteries