Digital Angle Protractor for Accurate Angle MeasurementFor helicopter angle calculation / miter saw taper / automotive test and repairs. Not only is it useful for woodworking projects, but it can also be used for many other uses around the home. It is useful for hanging pictures on the wall, finding a flat place when camping, placing decorative bricks in the garden. V-Groove Magnetic BackgroundThe digital protractor has a magnetic bottom with a v-groove, so you can quickly and easily attach to a table saw, band saw, metal bars and even round pipes. Grooves on 2 sides of the case for easy marking Large LCD Display"Taillight" LED technology for the brightest display - Screen size is 5 x 2.5 cm - It is easier and clearer to read the values even at night. Also, the LCD display shows low battery. Acoustic Alarm DisplayThe buzzer alerts you when it is in a horizontal or vertical position. Latch and Auto-Stop FunctionsLatch and hold functions allow precise measurement of absolute and relative angles, inclinations and slopes on any imaginable surface; Digital Level Box is powered by 2 AAA batteries (included) and automatically shuts off after 3 minutes without operation.