Measure 360 and Hold Data Protractor measuring range: 0-999.9 Resolution: 0.05(3') Accuracy: 0.5 The goniometer, can measure 360inner and outer angles, supports degree and degree or 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 not fully fix the angle4 in 1 Multifunctional Digital Goniometer: This product is a combination of protractor, spirit level, circular spirit level and ruler.It is calibrated by 3 bubble levels.Help you better measure the angle.(NOTE: This is NOT a digital level, there is no number displayed on the LCD, can only judge if the object is tilted).The main ruler is a dual scale in metric and inch. data easily and quickly.The digital angle ruler automatically shuts off after 5 minutes of inactivity to save power.The digital protractor also has a zero button that can be reset to zero 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, light 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 renovation, processing mechanics and other fields (including angle adjustment of table saws, miter saws, band saws, etc. Package Contents] 1 digital angle finder, 1 CR2032 battery 3V, 1 instruction manual. Passed CE and FC certification.