This product is produced by Osram and sharp laser the wavelength is 520nm, this is multi-functional, have a 360 rotation with magnet, project a laser green line on the floor, fix an iron nail on the concrete wall and project an indicator line, which is convenient to install the drawing board on the wall, and can also be adsorbed on the iron plate and on the ceiling and With vertical bubble and horizontal bubble precision reference if work with the spirit level to use it , will be better the Voltage is 2 AAA batteries the weight：100g. dimensions is 76x 50mm.