Using your Milwaukee 2104 headlamp is easy. First, insert the three included AAA batteries into the battery compartment. Then, adjust the strap to fit your head or attach it to your hard hat using the four included clips. To turn on the headlamp, press the power button. You can cycle through the five light output modes by pressing the button again. For the best light angle, use the seven adjustable positions to pivot the light head. When using it, keep in mind that the battery life will vary depending on the mode you choose. For longer runtime, use the low mode. To maintain your headlamp, keep it clean and dry. If it gets dirty, wipe it with a soft, dry cloth. Avoid exposing it to extreme temperatures or high-pressure water. And remember, the limited lifetime warranty doesn't cover the batteries, so make sure to replace them when they run out.