Large LED digital display screen, easy to read combining horizontal / vertical / slopes measurement This ruler is equipped with horizontal bubble for clear, stable, and accurate measurement When the horizontal bubble is at 0° or 90°, light will turn on The bottom of ruler is magnetically attaching and can be used upsides down, with the reading automatically flipping Builtin strong field, with strong adsorption, it can firmly adheres to ferrous metals, making it easy to work Multiple display units, including angles, slopes, and slopes ratio%, making unit switching simple and, Manufacturer: Shunzhong