Green Laser Light Pointer Pen is high quality laser pointer incorporates the latest technology in green laser optics and microelectronics. Use your laser pointer to point at any desired targets, projection screens or video monitors. Useful for presentations, museum and tour guides, pointing the stars and construction inspection. There is one key to open laser, use the key to open the switch lock in the tail. The green button notify us the laser is turn on, and the red button notify us the laser is turn off. It takes up to 10 seconds to start. It has rechargeable batteries with charger.