Specification: Lumens:2000 lumens. Diameter of the head:44.5mm. Length:142mm. Diameter of body:25.2mm. Battery:18650 battery. Weight:145g. Features: -The body of this flashlight is built of high quality aluminum alloy, and it has a very solid construction. -Internal wiring applies the high efficient booster circuit, and can utilize the batteries in the largest extent. -Excellent waterproof, suitable for outdoor environment, adverse weather conditions except for diving. -Focus function that allow the beam can be focused. Package included: 1 x C8+ SST40 Flashlight. Operation: - Driver instructions:(4modes). Now we offer another driver version, which has a simple 4 modes for switching, which is very suitable for ordinary users. modes: 0.1%-3%-30%-100%  max current output is 5000mA. Its biggest advantage is that no frequency can be seen in any mode, and there is temperature management. It can control the flashlight temperature not to exceed 55 degrees Celsius. If the flashlight temperature is below 55 degrees Celsius, it will output full current. If it is above 55 degrees Celsius, it will constantly adjust the current so that the flashlight will not overheat.