This flash light has multiple functions and settings all with just one button. If you press the button once it comes on extremely bright, hold the button for two seconds and it goes to a dimmer more, and hold the button again for two seconds and it goes into flashing mode, one click at any time To use the side lantern while the flash light is off, you hold the power button for two seconds (make sure to point it away from your face, because wow is it bright). To dim the flashing mode you press and hold the power button for 3-4 seconds, press it once to shut it off. It comes with a handy wrist strap. The best part is that this flash light is that it is rechargeable. I really like not having to keep buying batteries. I received this for testing purposes and have only written about my honest opinions based on my own personal experiences with this GMETAL-5 Innovative Dual Function Flash Light Lantern 500 Lumen Tactical LED Flashlight Torch USB Rechargeable PCB 18650 by Night ProVision. http://www.nightprovision.com/products/night-provsion-gmetal-5-innovative-dual-function-flash-light-lantern-500-lumen-tactical-led-flashlight-torch-usb-rechargeable-pcb-18650