Absolute and Relative Measurement: The magnetic digital level has absolute measurement for measuring the angle against the horizontal plane. This digital protractor and angle finder also features a relative measurement mode for quickly measuring angle between two measured surfaces for levelness Magnetic Base for Hands-Free Work: Magnetic V-groove base of digital level with slope percentage for easy attachment to ferrous metal surfaces such as pipes, steel construction framing, and metal fabrication with a rugged and durable aluminum frame for precision leveling measurement Automatic Digital Inversion Audio Indicator: The value reverses automatically when the electronic level is upside down. Backlit and ultra clear display helps you to work in dark condition. Audio indicator of magnetic digital angle gauge helps you always find 0 90 even with your eyes closed Four Units Two Precision Angle Ranges: Mini digital level angle gauge displays angle and bevel readings in degrees, in/ft, mm/m, and percent slope. It also has 0-90 and 0-180 angle ranges. You can choose the unit and range according to your reading habits and the needs of the measuring surface Accuracy Versatility: PREXISO digital torpedo level magnetic accurate to 0.1 at 0 and 90; 0.2 at other angles featuring with protractor, angle finder and level in one measuring tool. With the reading hold function, the digital inclinometer is convenient for recording the accurate measurement of the angles of different measured surfaces for woodwork, saws, building modifications, improving home drainage changes and evaluating leveling work