Using the Klein 935DAG Digital Angle Gauge and Level is easy. To measure an angle, simply place the tool on the surface you want to measure. If you're using the magnetic base, make sure the surface is ferromagnetic, like a conduit, so it attaches properly. For setting an angle, use the appropriate function on the tool to adjust to your desired angle. When using it as a digital level, just place it on the object you want to level and read the display. As for maintenance, keep it clean and dry. Avoid dropping it or exposing it to extreme temperatures. If it gets dirty, you can use a soft, dry cloth to wipe it. And always store it in a safe place when not in use.