Laser Level Square an easy to use layout tool Projects horizontal and vertical laser "chalk lines" on surfaces Dual diodes for making 90 degrees laser beam on any surfaces Two bubble vials Two suction cups allow the laser level square to be mounted onto the surfaces alignment guide for 90-degree layout-calculate and turning angles in 5-degree increments layout and partition installation. Square Laser: Generate 2 line at Right Angle (90 Degree) Ideal for floors, tiles, paneling, wall fixtures, wallpapering, stencilling, wainscoting, finish carpentry and more. Simple one button operation powers two perpendicular laser lines (90 degrees) on and off. Dimensions (L x W x H):150 x 73 x 50mm Wavelength: 630-670nm Power output: <5mw Accuracy: ±1mm/3m Available distance: 16m Battery type: 3 AAA 1.5V batteries ( Not included ) Operation temperature: -10~50°C