positive side of the 16340 battery toward the outside (the switch), the inside of the negative (inside), and then tighten the back cover Laser flashlight turned on, turn the focus head, the spot becomes larger, will be in the light near the light beam on the formation of the focus, the bigger the focus from the optical port closer, then find the focus can burn something Wear laser goggles when using high power laser pointer (https://www.boomlasers.com/1000mw_lasers/p-3.html) Please remove the battery when it is not in use for a long time Precautions Battery mounting method: the positive pole of the battery is facing the tail of the laser pointer Laser continuous lighting time is recommended not more than 3 minutes, or because of overheating will affect the life of LD If the laser beam brightness is greatly reduced, please charge the battery or replace the battery When not in use, remove the battery and place it where the child is not easily reached Laser beams are absolutely not allowed to irradiate the eyes of humans and animals when using them Don't point laser beams at aircraft or vehicles Don't hold a laser beam on the skin Guarantee We guarantee your laser are free shipping. We guarantee delivery to every country in the world, or your money back. We guarantee your laser will be free from defects for a full year from the date of receipt. We guarantee a 30-day money back return policy. FAQ Q: Is this laser power real? A: The data marked in the specifications is the minimum power, the actual power will be higher than data. Q: What is the minimum power required for burning laser pointer? A: Green/100mw, Blue/500mw, Red/200mw, higher power laser beams burn things more easily and faster, a thinner laser beam always burn things better than a wider laser beam. Q: What is the best laser color?