XTAR WK21 Review
Once again, thanks to Miles at Xtar for providing this light for review. The WK21 is a new light for the 1xcr123 compact EDC category. Like a few other new lights in this category, it also packs an XM-L emitter into a very small light, intended for keychain attachment. Unlike most other lights in this form factor with an XM-L, the Xtar supports and strongly promotes 16340 rechargeable use and does so with a very competitive price of around $38.
Obviously, the big story of this light is an XM-L and 16340 support, but the rest of the package is fairly impressive. Like the other lights in their new EDC series, it comes in a nice cardboard gift box. Within the box you will find a warranty card, a nice looking, light specific manual, and a keychain attachment. Other reviewers also received a spare o-ring, which was strangely missing in my review sample. The silver keychain attachment appears identical to the one on my ITP A2 SS. The box also includes a cut-out to include a battery in the package. I was happily surprised to see that my particular review sample actually also had an Xtar protected 16340 in the box. I do not believe the base retail package includes this, but I believe Xtar does provide this as an option for their dealers. If you were to gift this, you could always easily insert your own choice of battery into the cut-out in the box. The WK21 also comes with an attached clip that can be removed for those who wish to go clipless.
A neat feature is the removable magnet in the tail. It seems to be of reasonable strength, easily able to hold up the light horizontally or upside down. If you carry it where the magnet will be a problem, you have the option to unscrew the cover on the tail and take it out.
As you expect in this class, the light is a twisty, in the typical tighten on arrangement. It also uses Xtar’s unique five mode DIY driver, which is sequenced low-medium-high-strobe-sos. You loosen and retighten the head to run through the modes as you would expect. The light does have memory which seems to take effect after about three seconds. The driver gives you the option to remove any combination of the modes you want using a bit of solder, or you can just use a pencil for a temporary removal. There is now enough info on this driver out there now that I won’t go into detail on how to do this.
Style wise, this is a somewhat unique look, with a slightly enlarged head and a very thick, yet stubby body. It completely lacks knurling. The only feature that adds grip is the scalloping on the head. With the small size of the light and the larger head, the combination actually provides sufficient grip. However, the light overall is quite large for this category. The magnet in the tail adds a bit of length and it really is thick for this class of lights, which is exacerbated by the slightly oversized head. A look down the tube shows very thick side walls, enough where you could probably bore it out enough for an 18350. In general, there is just an awful lot of metal in this light, which adds weight. This light borders on overbuilt and as such it may be too large and heavy for a lot of people to consider use as a keychain light.
That's an ITP A2, not an A3 above.
BUILD QUALITY 4/5
Quite simply, the WK21 is built like a tank. There is just a ton of metal for such a small body and it feels unbelievably solid in the hand. The body strikes me as virtually indestructible. Its one of the first lights that just handling it made me want to throw it as hard as I could at something to see what would happen. I found no flaw in the anodizing. There is a very solid looking sliver spring on the negative end of the light in the body section. There is no spring at the head, which is typical of this light type. LED is well centered in the reflector and no noticeably dirt or flaws in the reflector or any other place in the light. The threads are buttery smooth and I detected no looseness. However, the protected 16340 provided by Xtar is a little longer than a standard CR123 and when I used this, it took quite a lot of force to tighten the head enough to turn on the light. One handed operation was not possible with the protected battery. Text lettering is reasonably sharp and even. One issue I had with my sample is that the o-ring does not seat itself very well. I have to use care when screwing on the head because the o-ring will start bunching in the gap. It’s probably just a bad o-ring on my sample and as soon as I find one of the correct size, I will replace it. The only other issue is that I notice is that it occasionally skips a mode when cycling through, usually either low or sos. To my knowledge, this is the first implementation of Xtar’s DIY driver in a twisty light so I wonder if that might have something to do with it.
LIGHT OUTPUT 4/5
The WK21 is a flood monster as you would expect. The light has a very wide spread to the corona, seeming to stetch almost 180 degrees outdoors (not truly 180, but it really is wide). Its notably more floody than the Xeno E03 XM-L. However, the interesting choice of a smooth reflector does provide a much more pronounced hot spot. That hot spot does not equate with throw as any throw provided by this light is more a result of sheer output. The beam has some slight rings on a white wall, but is not noticed in any real world application.
Xtar claims 500 lumens on high and this is clearly an overstatement. I would estimate 400 lumens at most using a 16340. You can tell from the ceiling bounce that the Xeno E03 is clearly brighter on a 14500 with its estimated 480 lumens. Pulling that much light from a 16340 will drain the battery very fast. Xtar only claims 20 minutes run time on high. I couldn’t figure out how to get a draw measurement given the design of the light, but given how much draw similar output compact lights have, I wouldn’t expect much more than that. I did run it for almost 20 minutes, so can verify that is at least that, but I didn’t want to try running any of my very small supply of 16340’s beyond that. Low mode is claimed at 10 lumens. This again is probably overstated, but an overstated low is actually a good thing here. The medium claim of 210 on 16340 actually seems about right, but I actually wish that this mode was a bit lower, perhaps more around the 100 lumen range. The light does use PWM. Its high enough not to be bothersome for the vast majority of people, but it was easily visible when projected against a fan.
The problem with this light is on CR123 primaries. It seems that this light is optimized for 16340 with no regard for primary use. Output was greatly reduced when using primaries. My advice would be not to bother with primaries except for as emergency backup.
L to R: ITP A2 SS R2 on 14500, WK21 on 16340, Xeno E03 XM-L on 14500
Xeno E03 on 14500
WK26 on 14500
ITP C7 14500
ITP A2 SS R2 14500
Balder SE-1 14500
Xeno E03 14500
This is a very solid entry for Xtar and I really have enjoyed working with it. I generally prefer the AA format for EDC so I don’t currently have any other CR123 lights, but I was impressed by the WK21. Its very well featured and if you want a super compact, very bright, XM-L equipped EDC, with true 16340 support, this really is a great option. However, if you plan on using mostly primaries, you are probably best served looking elsewhere.