Nitecore NU21 Ultralight Headlamp 360 Lumen
- 360 lumens max, 63 yard beam
- Up to 37 hours runtime
- 44 g (1.55 oz)
- 500mAh Li-ion, USB-C charging
- Red light, SOS and beacon modes
- 2.85 watts light source
Last refreshed Sep 10, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A feather-light rechargeable headlamp with an even beam that suits night runners and hikers. The battery is small, so long nights at high output need a recharge.
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ASIN: B0C77J4L7DModel: NU21Category: Headlamps
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Overview
Nitecore designs this headlamp for runners and hikers who want minimal weight, with a lens that spreads a soft, even beam for route finding. A built-in battery charges by USB-C, and the headband reflects and glows to alert traffic.
Barely any weight on the head and a uniform beam make it comfortable for long runs. The small internal battery cannot be swapped on the trail, so a power bank is the backup.
Who it's for
Runners, fast hikers and dog walkers who want little bounce and a beam that lights the path evenly. Long expeditions without power should consider a lamp on replaceable cells.
Pros and cons
- Even, soft beam
- Reflective, glow headband
- Red, SOS and beacon modes
- Lockout prevents accidental turn-on
- Battery not replaceable in the field
- Water resistant, no IP figure
- Modest beam distance
Performance notes
An optical lens with high light transmission shapes the output into a wide, uniform pool rather than a tight hotspot, which suits running. Runtime is governed by the small internal cell and drops quickly at the highest setting.
Specifications
| Brand | Nitecore |
|---|---|
| Model | NU21 |
| Dimensions & fit | |
| Item weight | 1.55 ounces (44 g) |
| Capacity & performance | |
| Light Output Maximum | 360 lumens |
| Power & efficiency | |
| Battery Type | Built-in 500mAh Li-ion |
| Light source wattage | 2.85 watts |
| Included components | |
| Included Components | Battery, headband |
| Warranty & support | |
| Manufacturer Warranty Description | 15-day DOA exchange, free repair within 24 months, limited warranty after |
| Other details | |
| Runtime | 37 hours |
| Water Resistance Level | Water resistant |
| Number of Light Sources | 2 |
| Beam distance | 63 yards |
| Charging | USB-C |
| Additional Features | Lockout mode, battery indicator, reflective and glow headband |
| Modes | White, red, SOS, beacon |
Frequently asked questions
How do I charge and look after the Nitecore NU21?
Charge the built-in 500mAh battery through the USB-C port. Use Lockout Mode in a pack to prevent accidental activation, and check the remaining power on the indicator.
Does the Nitecore NU21 have a red light?
Yes. It has red light, SOS and beacon modes.
Can the NU21 run on AAA batteries?
No. It uses a built-in Li-ion battery only.
What warranty does the NU21 have?
Defective units can be exchanged within 15 days, and free repair applies within 24 months of purchase.