Projects two plumb dots and one level dot. Tall profile for clearance of wood or metal drywall track. Locking compensator protects pendulum during transport. Visual out-of-level indicator 1/4 In.-20 tripod thread for use with most common tripods. Dust resistant construction. Laser wavelength 650nm +/- 10 nm (red), laser classification Class II. Includes (2) AA alkaline batteries.