2-in-1 Digital Goniometer: The angle ruler has the function of measuring length and angle. Also available in metric and imperial sizes. Easy to carry and use, great for woodworking, construction or drawing. EASY TO READ AND ACCURATE: The angle measurement tool with backlit LED display shows measurements quickly and clearly even in low light conditions. Accuracy 0.5; Resolution 0.05/3' Data hold function: the function keys of the digital display goniometer are easy to operate, with a locking knob, which can keep the angle unchanged during the measurement process, without worrying about data deviation, and the hold button helps users effectively record the angle Multifunctional Digital Protractor: The hold function stores the measured angles in memory, and the zero button resets the goniometer tool at any time. NOTE: You need to level the ruler and reset the value to zero before measuring the angle. Otherwise, measurements will be inaccurate.