Product features.1. Project a straight laser line on any surface, not just a point. Set the strait line to any angle. 2. Suitable for carpentry, stair risers, shelving, molding, tiling or any other job that requires precise alignment. 3. Double bubble level for accurate horizontal or vertical alignment and retractable push bar to hold the channel in place while working 4. On/off switch, very easy to use. Correct use : hold the laser marking instrument against the wall, the effective distance is about 5 meters, and cannot be used on the ground. The effective distance on the ground is about 1 meter. The longer the distance, the less obvious the light will be. Parameters: Product name: level meter Power supply: 2 x AAA batteries(without) Product use: pendant, door and window installation, tile, chandelier hanging, ceiling, etc. Tips: The product may be updated constantly, The Actual Product May Have Slight Differences Or Color Differences the color and appearance may be changed, please don't mind. And take a consideration before place the order if you have request for color or appearance. Notes: Product does not include batteries (2 x AAA batteries) Material: ABS colour: B-Blue Package Contents: 1 x level meter 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.