First off, let me state that this review is of an engineering, or pre-production sample of the product. Certain aspects may be different in the actual production version.

Right at the front is a glass lens which is advertised as having 2 separate types of coating. The outer surface is coated with "diamond" coating which prevents scratches, while the inner surface is AR coated providing optimum light transmission. The head houses an XR-E emitter which is very well centered with its medium textured reflector. The reflector is perfectly polished and machined with no marks or blemishes to be found. The entire emitter module seems to be sealed in my preview sample and could not be easily unscrewed. The bezel has a 3-point crenellation which is a change from the usual 6-point crenellation on most tactical lights. This does make the light wobble easier when placed head-down on flat surfaces. Most of the exterior surface of the head is covered in diamond textured knurling for grip, very well machined. Type 3 anodizing on the head is perfectly smooth and consistent.

The battery tube is also very well made. Like the head, almost the entire battery tube is covered in diamond textured knurling as well. The battery tube does have additional cosmetic touches machined onto it, 2 flat surfaces and 6 thin slots on either sides. Also, there's a slightly raised ring machined at the front end with 2 flat sides which serve as an anti-roll feature. Again, machining work is very well done, no roughly finished surfaces to be found at all. Type 3 anodizing is perfect and is of a very dark gray color, with an extremely subtle shade of brown. The internal of the battery tube has a bronze colored coating which I suppose is some sort of anti-oxidation chemical. It is a very light coat and has already rubbed off from its threads at the front end as can be seen in the gallery below. Speaking of threads, they are smooth, not too fine or too thick. They fit snugly and I did not experience any cross-threading during my tests.

The tail cap has a band of knurling about 1 cm wide which provides good grip. It also has 2 large slots on either side for lanyard or clip. Well machined all around, again no rough machining edges to be found. The black rubber button cap feels good, not too soft nor too stiff. The rubber cap does slightly protrude out, so the light can't tail stand. The tail cap houses a forward push button switch which allows for momentary operation on any mode, even strobe. One thing I don't like about the switch is that its mechanically a little rough. I experienced intermittent flickering during travel when half-pressing. This isn't an issue if you're simply using it for momentary on, however its not suitable if you want to do rapid momentary presses for signaling purposes. The switch module in my sample seems to be sealed into the tail cap as well and could not be unscrewed.

The output from the Defender is impressive especially on a 14500 cell, and even on an AA cell, thanks to its premium (at time of publishing) Q5 bin XR-E emitter. Runtime on a 14500 cell is pretty good, while on a regular AA cell is below average. Regulation is well maintained throughout the battery life. Overall the Defender performs best on 14500 3.7V li-ion cells, and still has the nice option of using regular AA cells. The color temperature on my sample is almost perfectly white with no noticeable cool or warm tint. After additional scrutinizing, I could only notice an extremely slight, cooler tint on its maximum brightness level. Beam profile is a smooth medium spot with a slightly yellow corona around the hot spot.

The smooth brightness ramping sequence means you can set it to almost any level between its minimum and maximum levels. It seems very similar to LiteFlux's ramping sequence, but with a much simpler user interface (no more estimating 1/4 turns). Its levels are controlled via very high frequency PWM which is totally undetectable by human eyes, again similar to the LF series. Switching of modes is done by twisting its head. Listed below are the sequences for changing brightness levels and modes.

Initial Position: Tightened head.
Mode: Maximum brightness or strobe.
- Loosen and tighten within 1 second to switch between modes.
Mode state is saved even after turning off.

Initial Position: Loosened head.
Mode: User-defined brightness.
- Tighten and loosen within 1 second to ramp brightness up.
- Tighten and loosen again within 1 second to ramp brightness down.
Switch off to set and save user-defined brightness level.

Please take note that while my sample has a buffer time of 1 second for switching, production versions will have a 0.5 second buffer time.

The Good - Machining, fit and finish is excellent. Simple interface for custom brightness setting. Smooth ramping of brightness level. Good output intensity.

The Bad - Below average runtime on AA cells. Slightly rough switch mechanism.

The Relative - Practically perfectly white tint. Forward push button which allows for momentary activation. Does not tail stand.

Head (front view).

Head (side view).

Head (rear view).

Battery tube (front view).

Battery tube (side view).

Battery tube (rear view).

Tail cap (front view).

Tail cap (side view).

Tail cap (rear view).