NITECORE E4K: Next Generation 21700 Compact EDC Flashlight

Features

• Utilizes 4 x CREE XP-L2 V6 LEDs with a max output of 4,400 lumens.
• An optical system combined with crystal coating and "Precision Digital Optics Technology" (PDOT).
• Max peak beam intensity of 11,100cd and max throw of 211 meters.
• Highly efficient constant current circuit provides a stable output for up to 700 hours.
• 2-stage side switch controls 5 brightness levels and 3 special modes.
• STROBE Mode uses randomly changing frequencies for stronger dizzying effects.
• A power indicator beneath the side switch indicates remaining battery power and can display battery voltage (±0.1V).
• Includes NITECORE 21700 rechargeable Li-ion battery (NL2150HPR 5,000mAh).
• Incorporates Advanced Temperature Regulation (ATR) module (Patent No. ZL201510534543.6).
• Electronic reverse polarity protection.
• Optical lenses with double-sided scratch resistant coating.
• Constructed from aero grade aluminum alloy with HA III military grade hard-anodized finish.
• Waterproof in accordance with IP68 (2 meters submersible) and impact resistant to 2 meters.
• Tail stand capability.

Specifications

• Length: 117.56mm (4.63")
• Head Diameter: 28.6mm (1.13")
• Tube Diameter: 25.8mm (1.02")
• Tail Diameter: 28.1mm (1.11")
• Weight: 80g (2.82oz)

Accessories Included

• NITECORE 21700 Rechargeable Li-ion Battery (NL2150HPR 5,000mAh)
• USB-C Charging Cable
• Clip
• Lanyard
• Spare O-ring
• Holster
• CR123 Battery Magazine

Battery Options

Technical Data

* The runtime of TURBO is tested without the temperature regulation. TURBO is only accessible when using a 21700 rechargeable Li-ion battery with an output over 15A.

Operating Instructions

Initial Use: Please remove the insulation film from the battery before the first use. When the flashlight is not in use for extended periods, loosen the tail cap by more than one turn to prevent accidental activation.

Battery Installation: Insert battery(s) with the positive end towards the head. Screw to tighten the tail cap. The power indicator will flash to show battery voltage upon insertion.

⚠️ Warnings:

• Ensure correct battery polarity (+ towards head).
• Use the battery magazine for 2 x CR123 batteries to prevent rattling and ensure stable contact.
• ⚠️ CAUTION! Do not look directly into the light; it can be dangerous for your eyes.
• When the power level is low, stop use and recharge the battery promptly to prevent damage.
• Remove batteries when storing the product for long periods to prevent accidental activation or leakage.
• DO NOT submerge a hot flashlight in liquid, as pressure differences can cause irreparable damage.

On / Off

The E4K features a 2-stage side switch. Full press to turn the light on or off. The light will access the last memorized brightness level upon activation.

Brightness Levels

When the light is on, half-press the Power Button to cycle through brightness levels: ULTRALOW LOW MID HIGH TURBO. Release the button at the desired level. The flashlight has a memory function.

Momentary Access to TURBO

• When the light is on, half-press and hold the Power Button for momentary TURBO. Release to return to the previous level.
• When the light is off, full-press and hold the Power Button for momentary TURBO. Release to turn it off.

Direct Access to ULTRALOW

When the light is off, half-press and hold the Power Button to directly access ULTRALOW.

Special Modes (STROBE / BEACON / SOS)

• When the light is on, full-press and hold the Power Button to access STROBE Mode.
• While in STROBE Mode, half-press the Power Button to cycle through BEACON SOS STROBE.
• From any special mode, a full press of the Power Button exits special modes and turns the light off.

Power Indication

The power indicator beneath the switch shows battery status:

• Upon Battery Insertion: The indicator flashes to show battery voltage (±0.1V). For example, 4.2V shows 4 flashes, pause, then 2 flashes.
• When Light is Off: Half-press the Power Button. The indicator flashes to show remaining power:
  • 3 flashes: Power above 50%
  • 2 flashes: Power below 50%
  • 1 flash: Power below 10%

Note: When using two CR123/RCR123 batteries in series, the indicator shows the average voltage.

ATR (Advanced Temperature Regulation)

The integrated ATR technology dynamically regulates the flashlight's output based on working conditions and ambient temperature to maintain optimal performance and prevent overheating.

Maintenance

Every 6 months, wipe the threads with a clean cloth and apply a thin coating of silicone-based lubricant.

Battery Replacement

Replace or recharge batteries when the output appears dim or the flashlight becomes unresponsive due to low power.

Warranty Service

All NITECORE® products are warranted for quality. DOA/defective products can be exchanged within 15 days of purchase through a local distributor/dealer. After that, defective/malfunctioning products can be repaired free of charge within 60 months from the date of purchase. A limited warranty applies beyond 60 months, covering labor and maintenance costs but not parts or accessories.

The warranty is void if:

1. The product is broken down, reconstructed, or modified by unauthorized parties.
2. The product is damaged due to improper use (e.g., reversed polarity installation).
3. The product is damaged due to battery leakage.

For the latest information, contact a local NITECORE® distributor or email service@nitecore.com.

All images, text, and statements are for reference only. Sysmax Innovations Co., Ltd. reserves the right to interpret and amend this document at any time without prior notice.

Company Information

SYSMAX Innovations Co., Ltd.

TEL: +86-20-83862000

FAX: +86-20-83882723

E-mail: info@nitecore.com

Web: www.nitecore.com

Address: Unit 6355, 5/F, No. 1021 Gaopu Road, Tianhe District, Guangzhou, 510653, Guangdong, China

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