Author Topic: Fenix TK21U Review  (Read 2573 times)

0 Members and 1 Guest are viewing this topic.

Offline KMA

  • Senior Member
  • ****
  • Posts: 842
    • View Profile
Fenix TK21U Review
« on: June 23, 2011, 12:04:36 AM »

I purchased the Fenix TK21U from Fenix Outfitters.

Comes with a holster, lanyard, o-rings, rear rubber clickie cover and instructions.

Fenix Outfitters gave some Powerizer CR123's.

Can use 2 CR123's or 1 18650 battery.

Uses XM-L U2 Led

SMO (Smooth) Reflector

Uses a spring to make contact with the positive anode of the battery. Cannot remove battery tube from head it's glued.

This is the where you access the light levels. Low, medium, high, turbo. Hold the button down you get into strobe. The strobe alternates between and fast strobe and medium strobe. To get out of strobe function just hold the button down until the strobe stops. The button is on a wider flat spot so it makes it easier to find the button.

Has square threads. Threads and o-ring came lubed.

Inside view of the rear forward cliclke.

The rear clicke only turns the TK21U on or off.

The Lumen and run times from Fenix.

Turbo - 468 Lumens,  1hr 50min

High - 180 Lumens, 5hrs 10min

Medium - 58 Lumens, 16hrs

Low - 5 Lumens, 220hrs

Distance 214 Meters or 702 Feet


I took Lux Readings with 1 AW Black 18650 Protected Battery 3.7V 2200mAH fully charged. I used my Meterman LM631 Light Meter.

I did not take any Lux readings or beam shots with the 2 CR123's.

Fenix TK21U, Turbo - 7510 Lux @ 1 Meter

Fenix TK21U, High - 2710 Lux @ 1 Meter

Fenix TK21U, Medium - 830 Lux @ 1 Meter

Fenix TK21U, Low - 90 Lux @ 1 Meter


Fenix TK21U @ 96"

Fenix TK21U, Medium @ 32'

Fenix TK21U, High @ 32'

Fenix TK21U, Turbo @ 32'

Fenix TK21U, Turbo @ 138'

Fenix TK21U, Turbo @ 158'


The Fenix TK21U2 XM-L build quality is excellent. Square threads and threads came lubed. The Black Type III Hard Anodize is excellent. Good color matching between parts and no flaws in the finish.

I was surprised at the size of the TK21U. I thought it would be much longer.

The mode changing button is very easy to use. It's made of metal. Fenix put the button on a wider flat area so it's easier to locate the button.

There is a anti roll device toward the end of the tail cap. Cannot tail stand because the rear clickie sticks out.

The tint of this XM-L U2 Led has a white hot spot. Around the hot spot the tint is a very slight green tint. It's just like most of the other XM-L CW (Cool Whites) I have. The slight green tint is more noticeable at lower levels. The low is a good low for reading.

The holster is OK. It uses thin material on the front of the holster so I don't think it will take much abuse or "wear and tear" for longevity.

Fenix claims a run time at Turbo 1hr 50mins for which isn't that bad IMO for an XM-L light.

On the box it says ANSI/NEMA FL 1

IPX-rated for waterproof.

I got the Fenix TK21U from Fenix Outfitter for $88.15. It was 10% off a Twitter Father's Day Special Discount.

« Last Edit: June 23, 2011, 12:36:58 AM by KMA »

Offline KMA

  • Senior Member
  • ****
  • Posts: 842
    • View Profile
Re: Fenix TK21U Review
« Reply #1 on: June 25, 2011, 05:32:02 PM »

The grip ring can be removed but there are threads showing.

Offline arewethereyetdad

  • Moderator
  • Flashaholic
  • *
  • Posts: 12649
  • 2008 National Champions
    • View Profile
Re: Fenix TK21U Review
« Reply #2 on: June 26, 2011, 01:23:11 AM »
Looks nice.  And powerful!  :thumbup: