CST/berger 57-LM800GR Single-Beam Dual-Slope Horizontal Self-Leveling Rotary Laser Horizontal self-leveling rotary laser kit with detector Single-speed rotation; dual-slope up to 10 percent; anti-drift system; motorized electronic self-leveling for speed and convenience Heavy duty glass-enclosed beacon and sealed housing is water- and dust-proof Includes rechargeable Ni-Mh battery, charger, LD400 detector, case, manual Low-battery indicator; 2-year warranty Class IIa laser product, &lt;1mW power output