Measure 360 and Hold Data Protractor measuring range: 0-999.9; Resolution: 0.05(3'); Precision: 0.5; The goniometer, can measure 360inner and outer angles, supports degree and degree/minute unit conversion. It has hold button and zero button. To lock the data, please press the HOLD button. (Turning the knob is only for loosening and tightening, can't fully fix the angle 4 in 1 Multifunctional Digital Goniometer: This product is a combination of protractor, spirit level, circular spirit level and ruler. It is calibrated by 3 spirit levels. Help you better measure the angle. (NOTE: this is NOT a digital level, no numbers are displayed on the LCD, can only judge if the object is tilted). The main ruler is a double scale in metric and inch. Large LCD display and automatic shutdown: This protractor has a large full-screen LCD display that allows you to read the data easily and quickly. The digital angle ruler automatically turns off after 5 minutes of inactivity to save energy. The digital protractor also has a zero button which can be zeroed at any position and is suitable for absolute and relative measurement. High Quality Material and Portable Design: The thickened and widened ruler body is made of high-strength nylon fiberglass construction material, which has good hardness, wear resistance, no deformation, no scratches, lightweight and durable 230mm, small , delicate design, easy to use and carry. Hanging hole design is convenient for hanging. Wide Range of Applications: This angle measuring tool is widely used in carpentry furniture, building decorations, school, home improvement, mechanical processing and other fields (including angle adjustment of saws table, miter saws, band saws, etc.)