Klarus XT21X Pro Tactical Flashlight Review
The Klarus XT21X Pro tactical flashlight uses one 21700 and a Cree XHP70.2 emitter. It features multiple switches, an orange peel reflector, and USB-C charging.
Official Specs and Features
Here’s a link to the Klarus XT21X Pro tactical flashlight product page.
Versions
There’s just one version of the Klarus XT21X Pro tactical flashlight. The light can be bought with or without a cell, though.
Price
MSRP of the Klarus XT21X Pro tactical flashlight is $109.95. Adding the 21700 cell seen in this article will bump the price up by $20.
There’s an introductory sale price on Amazon.com, too! That brings the price down to under $100 including the cell! Here’s a link to the official site for the Klarus XT21X Pro Tactical Flashlight.
Short Review
I consider this light excellent for the tactical flashlight category, at least in the default user group (tactical!). I appreciate that there’s also an “outdoor” setting since I will almost never want a light to start in Turbo (as this light does in the Tactical setting – the ideal setup!). Performance and build quality are both very good and the package is great, too.
Long Review
The Big Table
| Klarus XT21X Pro tactical flashlight | |
|---|---|
| Emitter: | Cree XHP70.2 |
| Price in USD at publication time: | $99.95 at the official Klarus website. |
| Cell: | 1×21700 |
| Runtime Graphs | |
| LVP? | Switch warning; low output |
| Switch Type: | Both |
| Quiescent Current (mA): | ? |
| On-Board Charging? | Yes |
| Charge Port Type: | USB-C |
| Charge Graph | |
| Power off Charge Port | With or without cell or tailcap: lowest three modes. |
| Claimed Lumens (lm) | 4400 |
| Measured Lumens (at 30s) | 3556 (80.8% of claim)^ |
| Candela per Lumen | 8.9 |
| Claimed Throw (m) | 336 |
| Candela (Calculated) in cd (at 30s) | 1039lux @ 5.455m = 30918cd |
| Throw (Calculated) (m) | 351.7 (104.7% of claim)^ |
| Claimed CCT | – |
| Measured CCT Range (K) | 6700-7300 Kelvin |
| Item provided for review by: | Klarus |
| All my Klarus reviews! | |
^ Measurement disclaimer: Testing flashlights is my hobby. I use hobbyist-level equipment for testing, including some I made myself. Try not to get buried in the details of manufacturer specifications versus measurements recorded here; A certain amount of difference (say, 10 or 15%) is perfectly reasonable.
What’s Included
- Klarus XT21X Pro tactical flashlight
- Klarus 5000mAh 21700
- 21700 to 18650 adapter
- Charging cable (USB-C to USB-C)
- Lanyard
- Nylon pouch
- Spare o-ring
- Powerbank adapters (2, 2 types)
- Manual
Package and Manual
Build Quality and Disassembly
This “XT” light from Klarus is really a big series of lights. You should be very familiar with the family. I’ve tested many of them – the XT21C, the XT2CR, the XT11GT Pro, and probably others. That’s a good thing, really. Klarus has found this niche and really rounded out the offerings in the category. It also means this is a honed product; all the kinks should be worked out by now!
Build quality on the Klarus XT21X Pro tactical flashlight is very good. One thing I like is that the threads on this tailcap are not as long as those of the XT21C, for example. Cell access is much quicker! Both the head and tail get a very beefy double-sprung spring. This is a reasonable, expected, and robust tactical setup.
Size and Comps
41mm (head diameter) x 29.2mm (tail diameter) x 163mm (length) and 171.5g without the battery.
If the flashlight will headstand, I’ll show it here (usually the third photo). If the flashlight will tailstand, I’ll also show that (usually in the fourth photo).
Here’s the test light with the venerable Convoy S2+. Mine’s a custom “baked” edition Nichia 219b triple. A very nice 18650 light.
Also above is the light beside my custom engraved TorchLAB BOSS 35, an 18350 light. I reviewed the aluminum version of that light in both 35 and 70 formats. I also reviewed that specific edition, the “Oveready BOSS FT Collector Vintage Brass” 35. I love it!
Retention and Carry
There’s a pocket clip included and attached. It’s a friction fit clip and lives on the tail end only. For belt carry it’s sufficient.
A nylon pouch is included. The carry is bezel-up only, and there aren’t any holes for in-holster use.
In fact, the carry orientation in the pouch is very specific because in the tail end there’s a little hard plastic cap that protects the tail switches from accidental activation.
The included lanyard could attach to the clip in the holes seen above, or in this hole on the tailcap. The tailcap will be much more secure.
Power and Runtime
The Klarus XT21X Pro tactical flashlight runs on a single lithium-ion cell. The required type cell can be added; it’s one of the kit options. This is a 5000mAh 21700 cell.
Unlike some previous iterations of this cell, the cell included here is a standard 21700 with a button top. Klarus kindly includes a plastic adapter for using a single 18650 cell, too.
The cell fits into the light in the usual way – positive terminal toward the head.
Below you can see a number of runtime tests. The Klarus XT21X Pro tactical flashlight claims 4400 lumens on Turbo. That’s quite a claim from a single emitter, but honestly, that’s practically what I measure. Initial output is well over 4000 lumens, so that puts the light within the 10% range. Even at 30 seconds, we’re still seeing over 3500 lumens, which is just incredible from one emitter. The stepdown is fairly dramatic. Output on the other two highest modes also steps down, but less quick and also less dramatically.
When the cell gets low (around 3.1V, it seems) the side e-switch will blink red. I observe (and the manual states) the light only switches down to a very low output when the cell voltage is low. The output is very low – not usable tactically, but certainly enough to find another cell or whatever.
There’s an indicator in the head of the flashlight, too. This indicator will light up for 5 seconds after the light is turned on. It indicates as follows:
Green: 70-100% capacity remaining
Orange: 30-70% capacity remaining
Red: <30% capacity remaining
Red flashing: <10% capacity remaining
Charging
The Klarus XT21X Pro tactical flashlight has built-in charging. The charge port is USB-C and has a snug press-in cover.
A USB-C to USB-C cable is included.
Charging looks fine, and seems to be the same circuit Klarus has used in the past. Peak current is around 2A, and the total charging time is around 5 hours.
During charging, the indicator in the head is red. When the indicator is green, charging is completed. If the indicator is yellow, something is wrong.
Powerbank
One feature that might be introduced on the Klarus XT21X Pro tactical flashlight specifically over the other XT generation of lights is that this UCB-C port can be used as a powerbank. Klarus even includes a couple of adapters, which both require the C to C cable. One of these adapters is a C to Lightning. So you’ll be able to charge an iPhone with this kit. The other is actually a C to male USB-A, which is not for powerbank features, but to allow charging of the Klarus XT21X Pro tactical flashlight itself. That’s a nice bonus, and I can see that being useful outside the XT21X Pro context, too!
Here’s some powerbank output testing. First, a bit of stress testing, where I run the current up high enough to cause the “reverse charging” to turn off.
After the stress testing, I run the light at some setting it seems capable of and then incrementally step down (from around 2.2A to around 1.1A to finally, around 0.5A.) The blue stuff in the center there is the powerbank going off and on at 2A. I don’t expect you’d experience this while charging a device, so it’s nothing to worry about. Either way, the powerbank function works fine, and you’ll definitely be able to get enough juice to your phone or whatever to cover emergency usage.
Modes and Currents
| Mode | Mode Claimed Output (lm) | Claimed Runtime | Measured Lumens |
|---|---|---|---|
| Turbo | 4400 | 2.5h | 4107 (0s) 3556 (30s) |
| High | 1500 | 4h | 1232 |
| Medium | 400 | 9h | 389 |
| Low | 100 | 30h | 96 |
| Moon | 5 | 200h | 5 |
Pulse Width Modulation
Here, as below, the mode order is represented: the graphs from left to right are in descending brightness. There’s no PWM to be seen!
Here you can see a “baseline” – a chart with almost no light hitting the sensor. Then there’s the Ultrafire WF-602C flashlight, which has some of the worst PWM I’ve seen. It’s so bad that I used a post about it to explain PWM! Here are multiple timescales (10ms, 5ms, 2ms, 1ms, 0.5ms, 0.2ms) to make comparing this “worst” PWM light to the test light easier. That post also explains why I didn’t test the WF-602C at the usual 50us scale.
User Interface and Operation
There are three (!!) switches on the Klarus XT21X Pro tactical flashlight. As this is a tactical-use light, the first switches to mention are both on the tailcap. One’s a paddle switch, and one is a mechanical clicky. It’s a fairly standard tactical setup.
These two switches are referred to as primary (the mechanical clicky) and mode (the paddle switch).
The third switch is an e-switch on the side of the head. This switch (called the “mode” switch) also offers an indicator function.
There are two mode groups. As shipped (and tested here), the light is in the “Tactical Setting.” Also available is the “Outdoor Setting.” Switch between the two in the following way:
From off, hold the paddle switch (“Mode”) until the indicator switch goes from green to red/green flashing. Then click the Primary switch. You can release or leave the light on; the group is changed.
| State | Action | Result |
|---|---|---|
| Off | Click Primary | Outdoor Setting: On (mode memory) Tactical Setting: Turbo |
| Off | Tap Primary | Outdoor Setting: Momentary (mode memory) Tactical Setting: Momentary Turbo |
| On | Click Primary | Off |
| Off | Tap Mode | Outdoor Setting: Momentary Moonlight (also sets Moonlight as the memorized mode!) Tactical Setting: Momentary Strobe |
| Off (Outdoor Setting) | Hold Mode >1s | Moonlight Steady |
| Off (Tactical Setting) | Hold Mode >2s | Strobe Steady |
| On | Click Mode | Outdoor Setting: Mode advance (ascending, all 5 modes) Tactical Setting: (descending, all 5 modes) |
| On (Tactical Setting) | Click and hold Mode >2s | Strobe (Upon release, the next click gives Turbo) |
| On (but only on from Mode switch!) | Hold Mode >1s | Off |
| Off | Click Side Switch | On (mode memory) |
| On (but only from Side switch!) | Click Side Switch | Mode advance (descending, all 5 modes) |
| Off or on from Side Switch | Double Click Side Switch | Strobe |
| Strobe | Double Click Side Switch | SOS |
| SOS or Strobe | Click Side Switch | Previous state |
| On (from side switch) | Hold Side Switch | Off |
I’m only fairly sure this table is sufficient for explaining the user interface. The graphic included in the manual is probably better.
LED and Beam
Klarus has used the high-output Cree XHP70.2 emitter in the XT21X Pro. This emitter really pumps out the lumens. A lightly orange peel reflector is used. It’s deep and fairly wide, too.
The bezel does unscrew readily. The bezel is somewhat aggressive, and as such allows light to shine out when headstanding.
LED Color Report (CRI and CCT)
CCT is unsurprisingly very cool on the highest output (left, below) but warms up to (a still very cool) 6700K on the lowest setting. CRI is also low, at around 70.
Beamshots
These beamshots always have the following settings: f8, ISO100, 0.3s shutter, and manual 5000K exposure. These photos are taken at floor level, and the beam hits the ceiling around 9 feet away.
Tint vs BLF-348 (KillzoneFlashlights.com 219b version) (affiliate link)
I keep the test flashlight on the left and the BLF-348 reference flashlight on the right.
I compare everything to the KillzoneFlashlights.com 219b BLF-348 because it’s inexpensive and has the best tint!
Conclusion
What I like
- Complete package
- USB-C Charging
- Interface which allows choice (specifically the Turbo to Low direction option in the Outdoor group, which is unusual)
- No PWM
- Really nice build quality (and feels important in hand)
- Updated user interface with good moonlight access in the Outdoor Setting
What I don’t like
- Cool white emitter
- At $109.95 it’s not inexpensive.
- The cell, which seems fairly standard, adds $20 to the price
Notes
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