The LT350 is our first light to offer the convenience of micro USB recharging. Now you have the added ability of charging your light from a laptop, tablet or a portable power pack. The exceptionally powerful beam is unleashed by a variable control magnetic switch. You control the intensity and the battery duration. Slide it forward to get 380 lumens for a 4 hour duration or pull it back to get 10 lumens for 20 hour duration.