[Review] Fenix TK11 TAC - I didn't know I needed this until I used it!

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rookiedaddy's picture
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[Review] Fenix TK11 TAC - I didn't know I needed this until I used it!

Was contacted by Fenix a few weeks ago and received a few lights for testing...

This is a review of the new Fenix TK11 Tac flashlight.

First thing first, the specifications of Fenix TK11 Tac:

There is a new switch design that Fenix try on this Fenix TK11 Tac, that is "Advanced Pulse-Frequency-Transmission System", and below is the promo slide for it:

ya, that doesn't help much...

so I ask Fenix and this is the reply I get:

great... now I have more questions than it answered...

did a patent search and found 2 patents that "might be" related to this APF: "CN 109945086 A" and "CN 111669880 A". For those who are interested, you can do your research into these patents. As the original filing is in Chinese, you may want to get someone to translate for you. Note that I could be very wrong about the patents in relation to the APF as I'm still confuse by most of the patent filing writings.

Fenix TK11 Tac flashlight:

a uni-direction pocket clip. it does not locked in place, so you can easily rotate the clip to any position you like, or remove it altogether.

Length and size comparisons to a few other flashlights:

following the tradition of TK-series, this new Fenix TK11 Tac is built like a tank.


I can easily operate the Tri-function Tactical Switch with one hand (2 fingers).


and it feels really great in hand.

The tail boot button is anodized metal, due to button is exposed/protruded, it's one of the easiest tactical tail swtich to operate and it's super silent too. This tactical switch offers 2 stages of operating level, half press for momentary On and full press for constant On. In both Momentary and constant On, you can switch mode by quickly half press the button to cycle the Low-Medium-High (only in Duty mode), this effectively giving us both Forward-clicky and Reversed-clicky functionality in the same light... something that I never thought I needed until I used this Fenix TK11 Tac. I did not know what I missed until I used it.


When the mechanical rotary is at this position, the light is in Duty mode. You can cycle the Low-Medium-High brightness by half pressing the switch.


When the mechanical rotary is at this position, the light is in Locked mode. If your Fenix TK11 Tac is Off when you rotate the mechanism to this position, Fenix TK11 Tac is effectively being locked out. You can't turn-On the light. If your Fenix TK11 Tac is already turned-On (Full press to engage constant On) when you rotate the mechanism to this position, then you are effectively locked in the chosen brightness, including strobe, and you can't turn the flashlight Off (unless you loosen the tailcap).

Besides offering a lock-out option with this rotary mechanism, you can also do a more traditional lock-out by loosening the tailcap quarter-turn.


When the mechanical rotary is at this position, the light is in Tactical mode. You only have momentary High mode (half-press) 1,600 lumens, constant High mode (full-press), and Variable Strobe mode (full-pressed-and-hold-for-1-second). Although Fenix says it's 0.8 second to engage the Variable Strobe mode... well... I ain't no machine so I go with a second here instead of counting the fractions. Also, it's OK if you hold the button for more than a second even after you've successfully engaged the Variable Strobe mode.

Below is a short video showing the Low-Medium-High mode cycle, and the Variable Strobe mode is out of the normal mode cycle as you need to explicitly engage the Variable Strobe mode by Full-Press-and-Hold sequence.


following are a couple of closed-up shots of Fenix TK11 Tac:

battery is inserted positive-side towards the head.

Note that Fenix TK11 Tac does not include any battery in the package.


O-ring and threads are generously lube.


spring at both positive and negative battery contacts to reduce recoil impact and to cushion any external impact (e.g. drop)


Luminus SST40 Cool White LED

The Tactical Strike Bezel... I do however wish that Fenix would offer a screw-on stainless-steel bezel.


My measure output of Fenix TK11 Tac:

The usual disclaimer: I do not claim the above measured lumens as authoritative nor an indication of over/under-stating the number given by manufacturer. It's calibrated against some known light output (e.g. SureFire, Elzetta, etc.) so take it with a grain of salt and just as a relative reading.

while below is Fenix quoted brightness and runtime table:


in my testing, however, the Turbo runtime is a bit shorter:

Fenix quoted the runtime using a 3500mAh Fenix 18650, while I tested using fresh new KeepPower and NiteCore 3500mAh 18650.

When checking back with Fenix on the runtime, I was informed that in Fenix's Lab condition, the Turbo ran for ~2-3 minutes before thermal throttling kicks-in. While in my environment, without fan-cooled, Fenix TK11 Tac sustain ~5 minutes at Turbo brightness before stepping down and when the temperature of Fenix TK11 Tac has cool down a little, there is a pick-up in brigntess (also depending on battery status). This explains the shorter total ANSI/PLATO FL-1 runtime that I'm getting from Fenix TK11 Tac.

With a fan-cooled condition, I'm getting a much longer Turbo runtime, ~15 minutes with KeepPower P1835U and ~8 minutes with NiteCore NL1835HP. This also explains the much shorter total runtime for the fan-cooled KeepPower P1835U, at approximately 74 total runtime minutes.


below are beamshots taken inhouse:

Fenix E28R is using an optics to give a bigger hotspot while Fenix TK11 Tac is using a smooth reflector, thus, Fenix TK11 Tac will appear brighter with our eyes focusing on the bright hotspot when compare side-by-side, although E28R lights up a larger area in front of user.


captured using a faster shutter speed. although Fenix E28R is quoted as 1500 lumens, but in my home-made lightbox, Fenix E28R is outputing ~1600 lumens too. Tint on Fenix TK11 Tac is also whiter.


In conclusion, the new Fenix TK11 Tac is definitely a flashlight model that I would highly recommend to any Law-enforcement, Military and Outdoor enthusiast. The new tactical switch at Fenix TK11 Tac is really very impressive, Not only it offers a very quiet and simple operation, but the way it makes it so straight forward for user to configure how one would operate Fenix TK11 Tac, has one of the best UX (User Experience) of any Tactical flashlights I've ever come across. Brova Fenix!

Thank you for reading.


still changing sig ::
Edited by: rookiedaddy on 10/10/2020 - 06:57
Lumeniac's picture
Last seen: 49 min 31 sec ago
Joined: 12/19/2016 - 13:47
Posts: 832
Location: Russia



as i suppose, this new tricky patented system is nothing but good (bad) olde PWM regulation

so i expected this model not to have such a good flat line of stabilization, impessed. 

 upd (impressed about turbo). high mode looks not that good.  

will get mine one this Monday and make review next week



Last seen: 1 day 15 hours ago
Joined: 08/03/2018 - 21:03
Posts: 668
Location: United States

I don’t understand why you would recommend a cool white flashlight to anyone.

You can't compare the big flashlight in the sky to the little flashlight in your hand.

Lumeniac's picture
Last seen: 49 min 31 sec ago
Joined: 12/19/2016 - 13:47
Posts: 832
Location: Russia

that is matter of choice

surprisijg amount of people would choose CW

i faced it even after offered them to compare cw and nw directly, when they bought lights from me


they picked cw to my surprise


u can do with cw in lots of situations when u dont need serious throw


i am not trying to say that cw is better than nw, of course) i liked thst fenix gave not bad NW, at least

but not this time, yeah. nevertheles,  when i tested tk22ue and ld30 i was sure it was 5700k, light doesnt feel this cold as i expected