The Nitecore T4K keyring light has an incredible maximum output of 4000 lumens from the 4 x Cree XP-L2 V6 LEDs and is powered by a built-in, 1000mAh li-ion battery. The flashlight is rechargeable via a USB-C port at the base of the torch and comes with a USB-C to USB charging cable. Offering a staggering output for the size of the light, the T4K is a technical breakthrough in the lighting industry! Nitecore have precisely calculated the display, quad-core emitters and dual buttons to pack them into an ultra compact housing without compromising on an excellent user experience. The Nitecore T4K provides two user modes: demo and daily. In Demo mode the torch will automatically turn off if there has been no operation in 30 seconds; in this mode a countdown will be displayed on the screen. In Daily mode the light stays on until turned off by the user. To switch between the modes, press and hold the power and mode buttons simultaneously until the LED flashes. 1 flash indicates the torch is in demo mode and 2 flashes is for daily mode. The torch features a multifunctional OLED real time display screen offering information on the battery voltage, brightness level, user mode and remaining runtime. Additionally, the T4K has a quick release keyring attachment so that you can easily remove the light from your keychain to use as a stand alone torch, then simply reattach when ready. Brightness Levels: Turbo: 4000 lumens - Short burst mode only High: 200 lumens - 2 hrs 45 mins runtime Mid: 65 lumens - 7 hrs runtime Low: 15 lumens - 21 hrs runtime Ultralow: 1 lumen - 67 hrs runtime Maximum beam distance 209 meters, waterproof to IP54 and resistant to impacts up to 1 meter. Includes: USB-C charging cable, key clasp.