Descriptions orizontal/vertical/universal Level ruler and angle finder functions. Pressing the HOLD Button in red to use data holding function for easy read and recording. Lock knobs easy to tighten, convenient and reliable measurement. Display unit: arbitrary conversion between degrees and minutes. Zero at any point:Any position can be cleared angle to 0, which is convenient for absolute and relative measurement. With automatic power-off function, save power consumption and extend battery life. Two rulers in metric and imperial systems are easy to read and write. Big size LCD digital display.