Specification: Material:Aluminum alloy.  Low voltage warning: yes.  Reverse polarity protection:yes.  Lens Type:Ar-coated lens.  Reflector:Smooth.  Switch position: Side.  Mode memory:Yes.  Tail stand:Yes.  Maximum charging current: 2A.  Battery charger includes: Not included.  Battery type required:1*21700 battery (not included).  Number of batteries required:1 .  Size: Head/body/tail diameter; 40mm/27.5mm/29.5mm.  length:143.8mm.  Product weight:145g.     Features: 1.click the button  ——>  flashlight is turned on with last brightness ——> press the button,brightness ramping up ——> release and press the button again,brightness ramping down.  2.flashlight off, press the button  ——>  moonlight mode  (0.2%)   [This brightness will not be remembered].  3.flashlight on or off, 2-click the button  ——>  turbo 100%.  4.flashlight off,3-click the button   ——>  strobe.  5.flashlight off,4-click the button   ——>  tactical mode, only 100% ,4-click the button again to quit tactical mode.  6.flashlight off,5-click the button   ——>  voltage detection .  7.flashlight off,6-click the button   ——>  normal ramping mode switch to 4modes 1%-10%-40%-100%.  8.flashlight off,10-click the button   ——>  Lock mode,The flashlight will flash once under any operation, which means the flashlight is locked.10-click the button again to quit lock mode,Please note that this is the only way to unlock.     Package included: 1 x M21F KW CULPM1.TG/SFT40 Powerful 21700 Flashlight (battery not included)a