The CST/Berger LM800 Series was voted one of the years 100 Best New Products by Professional BuilderThe CST/Berger 57-LM800GRPK is a Single-Beam Horizontal Self-Leveling Rotary Laser Package. It has a visible beam laser which is used for both general construction and interior work. It has single speed rotation with dual slope capability up to ±10%. The anti-drift system gives signal to the operator when unit is moved out of position. The battery level indicator is given so that user doesn’t run out of power at the wrong time.