As powerful as any primary light and as small as any backup light, the Nitecore E4K Rechargeable LED Flashlightpacks more lumens and more output options than most full-size duty lights—ensuring you'll reach for it time and again whether you're on duty, on the job, or on the trail.

Its four Cree XP-L2 V6 LEDs are driven by a high-capacity 21700 Li-ion battery with outputs ranging from an ultra-low 2 lumens for doing tasks like reading without disturbing your bunk mates or checking IDs up to a darkness-piercing 4400 lumens for searches and to clear rooms safely. Three intermediate outputs allow you to select the perfect output for any situation you might come across. In addition to the five output intensities, you also have three specialty modes: An SOS distress signal, a location beacon, and a disorienting strobe. You further have the option for instant access to the turbo mode or the strobe mode depending on your situation or use. All modes and outputs are accessed from a single push button located on the handle with an intuitive interface.

To hold up to daily use, the body is CNC machined as a single uni-body to limit parts, reduce weight, and better dissipate heat. The housing is further treated with a hard-anodized finish that resists scratches. O-rings seal the interior to an IP68 rating, making it dustproof and waterproof to a depth of almost 7 feet, and it is also impact rated to handle drops of over 3 feet. Its compact and lightweight design brings it in at under 5 inches long and under 3 ounces in weight, so you can carry it all day and night and you'll barely notice that it's there. Nitecore includes a holster and a reversible clip to give you multiple carrying options, as well as a battery cartridge that lets you use two of the more common CR123A batteries if you get stuck without the ability to recharge the included 21700 battery.

Five Outputs from 2 to 4400 Lumens    Four High-Output Cree XP-L2 V6 LEDs    SOS, Beacon & Strobe Modes    Push-Button Switch with Output Memory    Instant Access to 2-Lumen & Turbo/Strobe    Hard Anodized Aluminum Uni-Body Housing    Impact Resistant and Submersible    Multiple Protection Circuitry Systems    Runs on 1 Included 21700 Li-Ion Battery    Capable of Running on CR123A Batteries

• Ultra-low 2-lumen output is ideal for reading without disturbing others
• Low 50 lumens will light a tent, closet, or car trunk for finding gear and checking what you have
• Medium 320-lumen output lights rooms, truck beds, bed caps, and other larger areas for navigating and moving freely around
• High 1050 lumens is ideal for hiking and navigating safely in total darkness
• Darkness-piercing 4400 turbo mode outputs massive amounts of light that illuminates all nooks and crannies for safe searching and clearing
• Four high-output Cree XP-L2 V6 LEDs work together to produce the impressive 4400-lumen max output
• Deep smooth reflector combines the output from all four LEDs into a single beam
• SOS mode: Automatically cycles through the Morse Code distress signal to alert searchers if you are incapacitated
• Beacon mode: Pulses a flash of light at regular intervals to show your position
• Strobe mode: Bright random frequency strobe can be used to disorient a possible threat

• Type: Push button
• Location: Handle
• Constant-on activation only
• Large textured button cover is easy to find and use, even in cold and wet weather or while wearing gloves
• Last mode memory returns light to the previous output level when it is turned on again—only applies to standard outputs, not to strobe/SOS/beacon
• Instant access to ultra-low output
• Two "User Mode" options: Default "Daily" mode provides instant access to turbo mode; "Tactical" mode gives instant access to strobe
• Simple and intuitive user interface with single switch

• Corrosion-resistant and durable uni-body aluminum housing
• Scratch-resistant Type III hard anodized finish
• Tempered glass lens window with scratch-resistant hard coatings
• IP68-rated to be waterproof and submersible to almost 7 feet and dustproof
• Impact resistant to over 3 feet
• Tail stand capable for hands-free use
• Palm-size compact length of under 5 inches
• Lightweight design at less than 3 ounces
• Includes holster, lanyard, and removable pocket clip

• Runs on one included high-capacity 21700 5000mAh Li-ion battery
• Integrated USB-C charging port on the battery allows users to plug the included USB charging cable directly into the battery without the need for bulky charging bases/cradles
• Digitally regulated output maintains a consistent beam intensity throughout the battery charge
• Advanced Temperature Regulation (ATR) system monitors the internal temperature and automatically steps down the output intensity to prevent damage due to excessive heat
• Reverse polarity protection prevents damage if the battery is installed backwards
• Integrated battery level indicator on push button
• Capable of running on two user-supplied CR123A batteries using the included battery cartridge; outputs and runtimes may be affected

Related Questions and Answers

Q: 1. i have one and will not turn on and i charged it i belive it as a locking feature that will not let it go on can you tell me how to unluck it ?

A: Hold the power button for 3 seconds then quickly press the button to turn on.

Q: 2. how to charge for rechargeable batteries?

A: This flash light comes with a rechargeable battery and charger. So it just plugs in and you put the battery on the charger.

Q: 3. When charging the unit the blue light comes on. Does that mean it is fully charged or simply charging. How do you know when it has reached a full charge?

A: According to Nitecore, a steady blue light means it's charging. When fully charged, the light will turn off. https://bit.ly/2UEPK2M

Q: 4. How do you get out of strobe mode? The low level is fine but if I double click to get to the high intensity I get a fast blink

A: Unfortunately, a strobe mode is not offered on this model.

Q: 5. Will these products work with a D Cell bettery spacer, like the one offered by watson on this site? I am looking for something to power my Casio WK 6600.

A: Unfortunately, this battery would not be compatible with a D-Cell spacer.

Q: 6. Is this a red light?

A: The Nitecore TUBE v2 LED Key Chain Flashlight (Black) BH #NITUBEV2BK is a white light.

Q: 7. Does this fit the Nucleus Nano hand wheel?

A: Yes, the Tilta Nucleus-Nano Wireless Focus Hand Wheel Controller is compatible with the Nitecore 14500 Li-Ion Rechargeable Battery (3.7V, 1000mAh).

Q: 8. What’s the difference between the bb2 and the bb21?

A: In most regards the Nitecore BB2 Rechargeable Cleaning Blower for Cameras & Electronics and the Nitecore BB21 Rechargeable Air Duster (B&H # NIBB21) are very similar dusters. The newer BB21 has a newly designed dual-button interface that makes it easier to use, and it has a lock mode. Additionally, only the BB2 includes a high-CRI LED light.

Q: 9. What product will recharge the included battery?

A: Please review the following item for your rechargeable battery needs. Watson Dual Rapid Charger for 3V CR123A and CR2 Lithium Batteries with 2 CR123A Batteries BH #WAADC3VCR123 • MFR #ADC-3VCR123A https://bhpho.to/3HZFJ7Y

Q: 10. can I charge on regular charger? not on usb c.

A: Yes the Nitecore UFZ100 Rechargeable Battery can be changed in a standard FZ100 compatible battery charger. It does not need to be connected via USB.