[Review] Nitecore MT21C ... Adj Angle Head+Metal Switch+Mag Tail

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CivilGearReviews's picture
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[Review] Nitecore MT21C ... Adj Angle Head+Metal Switch+Mag Tail

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Hi all! Nitecore sent me this light to test so I wanted to share my thoughts with you.


Two new firsts for Nitecore, an adjustable angle flashlight, and an illuminated metal switch! Overall, this feels like a great selection for someone who could use a hands-free headlamp but declines to actually wear a light on their head (or an 18650) but would rather clip-it, hang-it, or stick-it close by to do their work. With a tilting-head, wide 90-degree beam, and 1,000 lumens, the Nitecore MT21C is a very nifty companion!


Nitecore MT21C Flashlight Review CivilGear 000


Nitecore MT21C Flashlight Review CivilGear 002

 Link to manufacture product page: http://flashlight.nitecore.com/product/mt21c



Overall, this is a very adaptable light with many attachment options. I really like the new metal switch as it looks and feels very durable and could survive in a tool bucket with no problem. 



If not stated beforehand, say battery format and quantities ie 2×18650





Other Dimensions

  • Length 131 mm / 5.15 in
  • Head Size 25.4 mm / 1 in
  • Weight 103.5 g / 3.65 oz



I received an early release with no box but I likely received all the accessories and the rest is easy to guess:

  • MT21C
  • Pocket Clip (attached to the light in this picture)
  • Standard Lanyard
  • 2x o-rings
  • Manual (pdf)
  • Warranty Card


Nitecore MT21C Flashlight Review CivilGear 025



 This is the only version.  



 Current price is about $60 (buy links at the very end of the review)




The overall feeling is sturdy and especially with the new metal switch (a Nitecore first if I’m not mistaken)! The body has smooth but still tactile knurling along with a minor bit of anti-roll shape below the switch.

The switch feels a little stiffer but I think it’s because there is a little travel before it reaches the contact. I also love the look of the illuminated indicator ring around it, so bright and clear instead of behind a rubber switch cover.

The tilting head appears to be held at angle by use of a spring loaded ball bearing. The tilting head on mine came pretty well lubed, trouble is that it gets very well exposed when you tilt the head down. T

he hanging loop is pretty sturdy but feels a little short so you get the most out of it by angling the loop back a little. The loop can also be removed.

The tail cap is very flat and also is magnetic.



The light comes apart in 3 pieces and again, similar to the MH23, it feels easier to take the head off than the tail cap; it seems there are half as many threads (3) in the head. The tail cap has quite a beefy spring and has a decent amount of tension but not too tight. There is no rattle when shaken. It appears there is no physical reverse polarity protection so flat-top cells should work in this light.



The light has a brand new pocket clip design with an extra wide connecting band and a wider and longer clip. The clip is super strong and is also very hard to get off.

The light comes with a lanyard but I’m not sure where the best connection point is. I think it’s meant to go on the eye-loop that just seems a bit far away from the end. I guess you can also loop it to the clip. Other than that there




The light uses the CREE XP-L HD V6 LED rated at 1,000 lumens.



Nitecore does not advertise the angle of main LED but from what I’ve collected it seems to be a 90 total degrees spill with a 20 total degree spot. The spill is a bit dim but I’m impressed how wide it is. 

The first rectangular graph is cut across the beam and helps a bit better to see what angle the spill starts at as usually it is quite a bit dimmer then the center. It’s quite possible that a very low lumen outer spill might not register using these methods. The percentage is a relative comparison to the brightest light recorded (generally, in the center).

The second, polar graph, is a simulation of the light along the beam.

Currently, these readings are strictly sensor recorded, and are not adjusted based on human perception of light but may be an interesting idea for the future.



The tint is cooler than the Nichia 219B (in the Nitecore MT06MD) but it’s not the coolest I’ve seen.

Nitecore MT21C Flashlight Review CivilGear 037



I’m pretty easy to please for output levels, but it’s easy to be satisfied when there are a total of 5. Below is a night shot video of me going threw all the output modes. Below that, there are stills of all 5 primary modes.

Ultra Low->Low->Mid->High->Turbo



 All the pictures below are taken with the light in TURBO.




The light uses 18650, button-top or flat-top cells but no battery is included with the default package. However, when using a shorter flat-top cell, if the light his hit slightly on the bottom the battery will loose contact momentarily.




You can check the battery level by, when off, pressing the switch once, or by loosening the tail cap and tightening it again. The indicator will blink out the voltage of the cell, for example 3.7 volts will display as 3 blinks, a pause, and 7 more blinks, then ends.

Nitecore MT21C Flashlight Review CivilGear 026


There is no drop-and-find mode, or what Nitecore usually calls a “positioning” mode. Since you could wear the light on a backpack strap, it might be neat to have this features.




I measured the light output in relative LUX and I have not spent time yet to calibrated for lumens or factored % of max output. The charts I’ve provided, while are literally quantitative, I suggest using as a qualitative reference for how the output may behave over time; typically lights aren’t left on this long and the max output can be reset. It’s worth to note that the runtime table provided by Nitecore states, “Runtime for TURBO is calculated based on theoretical arithmetic.” so this isn’t physically reproducible in my tests.

PWM check using a 50 millisecond test period with a sampling rate of 3,000 times per second. 

Temperature measurement condition is at room temp and currently no fan cooling.

I am still very new at doing these types of measurements so I am no authority on on this subject, but please let me know if things don’t look right or you see anything that I could do to improve for next time.



The below battery was either provided or recommended by the manufacturer. Make sure that you carefully research any cell you are considering using before purchasing.

  • Brand: Nitecore
  • Model: NL1832
  • Positive Contact: button-top
  • Protection circuit: protected
  • Voltage: 3.7
  • Capacity: 3200 mAh
  • Cell Length: 69mm



Runs on turbo for about 5 min and over the next 10 min gradually steps down to 40% output. Very Interesting at the end that there is a gradual decrease instead of a final drop, which is kind of nice that you aren’t suddenly left in the dark. I did a bunch of resets to see how high I could push the temperature; however, the resets only let turbo run for 1 min before it drops down again, due to high temperature.

For the below chart: BLUE is light output, RED is temperature “out the front” directly in front of the lens, ORANGE is temperature on the outside exterior of the head near the LED.




A max body temp of 119°F  was initially reached after 5 min when the TURBO ended; then, after many turbo resets the body temp reached 126.5°F. Overall, the body temperature is well regulated and you have to really keep pumping the turbo to get into +120 degree range.



A max out-the-front (OTF) temp of 202°F  was observed after 5 min when the TURBO ended; then, after many turbo resets the OTF temp did not exceed the intial temp.



There appears to be no PWM on any constant mode. 

For comparison, the second graph shows PWM varying from 0 to 120 lx on the LOW mode on the Nitecore R25 flashlight.



Strobe frequency is about 18hz.



Frequency is 1 flash every 2 seconds.



Overall, this UI is OK but a little slow for me as like to be able to turn on the light quickly when I need it. My ideal Nitecore UI with electronic single-stage is the HC33 and this UI is not too far from it but the MT21C has a long wait to turn on and there is no mode memory. The single click, in off checks the battery but that’s redundant as you can easily unscrew the cap a quarter turn and tighten and get the same thing.

Summary and other thoughts:

  • Does have shortcuts to lowest and highest
  • Has a momentary turbo, only accessible in OFF
  • Does not have mode memory
  • There are two ways to check the battery level
  • No drop-and-find mode




  • Neat angle-adjustable head
  • Lots of attachments options, more beefy magnet than usual
  • Metal switch cover is very neat and durable
  • Love the blue indicator light ring
  • Wide beam for a handheld light
  • Very strong pocket clip
  • Stable output and neat 15min run-down time at the end to warn of depleted battery.


  • Might of liked USB charging
  • No mode memory
  • Redundant battery check options
  • No “drop-and-find” mode
  • The tilting head is a little bit of exposed lube when it’s tilted
  • Note that when the light is angled down pointed away from you, the power switch is on the left had side, not the back, also may not be great for lefties


The current price for the light is about $60 USD and if you appreciated my review and would like to support me, feel free to check out this product on amazon using my affiliate link (does not cost you more, amazon gives me very small % of their profit):

Amazon Link: NITECORE MT21C 1000 Lumen 90 Degree Tiltable Head Multifunction LED Flashlight



  • CivilGear Reviews received this product for testing and providing an honest review.
  • CivilGear Reviews was not paid for writing this review.
  • CivilGear Reviews is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com
Edited by: CivilGearReviews on 05/06/2018 - 02:14
vresto's picture
Last seen: 1 hour 20 min ago
Joined: 01/25/2011 - 17:49
Posts: 1040

very nice review,very nice flashlight..sure first angle from them..well..if i wanted to buy Rofis..this is more quality brand,same price almost…thanks a lot:)

EDC-Amutorch X9 XHP50 nw,Sofirn If-25A cw

Headlamp-Thrunite TH30 nw