Specifications: Type:Type 1 - 4 Modes.  Type 2 - 12 Groups.  Material:Aluminum Alloy.  LED:Osram KW CULPM1.TG 6500K white tint.  Low voltage warning: Yes.  Reverse polarity protection:Yes.  Lens type:Ar-coated glass lens.  Reflector:Smooth reflector.  Mode memory: Yes.  Tailstand:Yes.  Battery included:No.  Required battery type:21700 or 18650 lithium battery .  Required battery quantity:1pcs.  Driver:4 modes 0.1%-3%-30%-100% / 12groups, max current output 6000mA, Temperature protection management inside.  Length / Diameter:124.4mm / 27.2mm.  Weight:91.6g.  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 6000mA.  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.  Driver (sst40 12groups): Max current output is 6000mA.  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.     Package included: 1 * S21B Flashlight.