4 in 1 Multifunctional Digital GoniometerThis product is a combination of protractor, spirit level, circular spirit level and ruler. This helps you measure the angle better. Supports unit conversion to degrees and degrees or minutes. (NOTE: This is NOT a digital level. It will not display the number on the LCD screen, it will only help you determine whether it is horizontal or vertical or not) Measure 360 and keep dataProtractor measuring range: 0-999.9 Accuracy: 0.5. The display has a hold function to freeze movement for greater accuracy. To press the red HOLD button instead of turning the knob. (The knob is only for loosening and tightening. It can't fully hold the angle with force!) Large LCD Display and Auto Power OffThis protractor is designed with large full-screen LCD display , easy to measure and read. The digital angle ruler automatically turns off after 5 minutes of inactivity to save energy. In addition, it supports degree and degree or minute unit conversion. Wide ApplicationsThis angle measuring tool is widely used in carpentry furniture, building decoration , school, home improvement, etc. household, mechanical processing and other fields (including angle adjustment of table saws, miter saws, band saws, etc.)