Digital inclinometer with a measurement range of 4x90° (0~360°), displaying angles and grade readings in degrees, in/ft, mm/m, and percent grade. High-precision digital goniometer measures or adjusts angles with ±0.1° accuracy at 0° and 90°; ±0.2° accuracy for other angles. Resolution: 0.05°. Features a built-in beep alarm that sounds at 0° or 90°, with increasing frequency as the angle approaches these values, achieving a constant tone within ±0° or 90°. Includes a data hold function to freeze and save measurements. Auto-reversing display allows for easy reading when the device is inverted. V-groove base with strong magnets securely attaches to curved or cylindrical surfaces such as pipes or metal shafts. Backlit LCD screen enhances visibility in low-light conditions. Offers two measurement modes: absolute and relative. Press the "zero" button to switch between modes at any position for quick angle measurement between two surfaces. Can be used as an inclinometer, level, or slope gauge. Note: This product includes only the slope ruler and no additional accessories shown in images.