4 Two vertical lines intersect at a 90 angle, allowing users to quickly visualize and complete a square layout. Two 360 horizontal planes and two 360 vertical planes are intersected and connected at a 90 angle to complete the visual layout of the square and achieve precise positioning. Self-leveling and manual mode- With the intelligent pendulum system, this laser leveling tool can automatically tilt 3, and the alarm will be activated until we put it into position horizontal. High brightness and high precision: We use a green laser beam, 4 times brighter than the traditional red laser beam. It is still very precise and clear in the sun or at dusk. Wide application: Horizontal/vertical lines can be selected individually or simultaneously depending on the job site application. Ideal tool for installing light fixtures, hanging pictures, wall or floor tiles, doors, windows or furniture, hanging wallpaper, concrete, construction, cabinets, painting and more. Durable Design: The top over-molded metal laser window is waterproof and dustproof to IP54, ensuring you can work well in hazardous working conditions. Portable bins are designed for clean, secure storage and easy to carry with you.