Important: The accuracy is rated within distance of 10 meters. Under unfavorable conditions, such as in extreme interior illumination, transparent surface(eg. glass, water), porous surface(eg. insulation materials) or reflecting surfaces(eg. polished metal, glass) or very rough surfaces(eg. rough cast, natural stone), the tool's measuring range and accuracy will be reduced. Spirit Level Small with 2 Bubbles Tile Lasers Level & Square Lasers Line and Point Laser Level with 360Rotating Base Working Range 30FT/10M 30FT/10M 30FT/10M Continuous Working Time 4H 10H 12H Weight 25g 220g (without battery) 158g (without battery) 2 Bubbles.