Johnson's 40-6647 self-leveling cross and line laser combines the features of a cross-line laser with an additional 90 deg plumb line, useful for checking square reference of beams, posts or any other object. It features GreenBrite technology, making the beams 400% more visible than red beams for working in sunny or brightly lit conditions. Thanks to the laser's visual out of level indicator, you'll never need to worry about accuracy - if the laser can't self-level, it will alert you by flashing the beam. With the included magnetic target, magnetic bracket and tinted glasses, you'll have everything you need to get your job up and running!.