4 in 1 Multifunctional Digital GoniometerThis product is a combination of protractor, spirit level, circular spirit level and ruler. Help you better measure the angle. support converting degree and degree/minute units.(NOTE: It is NOT a digital level. Will not show number on the LCD, it will only help you to judge whether it is horizontal /vertical or not) Measure 360 and Hold DataProtractor measuring range: 0-999.9; Accuracy: 0.5. The screen has a hold function to freeze movement for more precision. To press the red HOLD button instead of turning the knob. (The knob is only for loosening and tightening. It cant fully hold the angle tightly ) Large LCD Display Auto StopThis protractor is designed with large LCD display full screen, easy to measure and read. The digital angle ruler automatically turns off after 5 minutes of inactivity to save energy. Also, it supports degree and degree/minute unit conversion. Wide ApplicationsThis angle measuring tool is widely used in carpentry furniture, building decorations , school, home improvement, mechanical processing and other fields (including angle adjustment of table saws, miter saws, band saws, etc.)