1. It uses high-precision laser diodes and conical mirrors. The emitted laser line is accurate, bright, and its brightness is adjustable. 2. It is equipped with a self - inspection and calibration function. The self - leveling is ≤3°. However, if the angle is greater than 3°, the laser lamp will continue to flash, and the laser level will alert the remote control. H = vertical line, V = horizontal line. You can easily adjust the brightness of the laser lamp by pressing the + or - buttons. 3. Press and hold the OUT button for 3 seconds to enter the tilt mode. Then you can place the laser tool at any angle to project a tilted line. 4. Short - press the OUT button or long - press the H or V button, and you can freely adjust the laser brightness according to the work situation.