Attention: During operation, be careful not to expose your eyes to the emitted laser beam. It is best done in low light, as strong light can affect the laser. Laser level tool with one bubble vials , It can be used outdoors for construction measurement on site, and indoors can be widely used for decoration, hanging pictures, hanging mirrors, installing curtain rods and other household items name: laser level battery:Built-in rechargeable lithium battery Power supply:DC3.7V Lithium battery: 751525 (230mah) Laser color: Green laser Measurement Model:Vertical and horizontal 2 cross laser lines Precision:1-2mm Wavelength:515-650mm Type:Vertical & Horizontal Lasers Line width:1-2mm Working distance:10-30m Working principle:Horizontal bubble centered horizontal Fixed mode: Fixed magnet Colour:Black Material:PC Package Contents: 1 * laser level Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.