The head of the K1 is entirely made from solid stainless steel which gives it a slightly hefty and robust feel. The stainless steel head is heavier than the rest of the body and provides added protection if the light is dropped as compared a aluminum bezels/heads. Right up the front sits a regular glass lens. Behind the lens is a smooth reflector, coating is smooth and consistent. The dark areas you see in the image to the right are reflection artifacts. There's a rubber o-ring between the reflector and lens for waterproofing. The entire exterior surface of the head has a corkscrew knurling design to it which gives it a different look as compared to most other lights which use the common diamond texture. This corkscrew design is cut quite deep and provides very good grip, thought it doesn't really matter with the K1 since it's not a twist activated light. Threads on the rear end of the head is smooth and cleanly cut, a rubber o-ring sits just above the threads for waterproofing. The PCB showing at the rear end has clean contact for the "+" battery end.

The battery tube of the K1 has 6 flat faces machined running down almost the entire length of the body. This actually feels better in hand and provides a better grip to me as compared to a cylindrical body design with knurling. The front end of the battery tube is slightly wider as it has to mate with the slightly larger head. The battery tube has a thicker wall than most other lights. The exterior of the battery tube is entirely coated in black Type 3 anodizing. Finish is smooth and consistent with a slightly matte finish, no marks or smudges were found. Threads as both ends of the light are left bare which means that it can't be locked out by loosening the tail cap. The tail cap has a squarish design with 4 large flat sides and provides good grip for battery changes. A reverse push button switch is housed inside the tail cap which has average travel and provides a very positive tactile feedback. I found the switch to be a little more stiff than most, depending on your preference this could be a good or bad thing. The rubber switch cap has a smooth finish on the exterior and is thick enough to last. It sits recessed inside the tail cap so the K1 is able to tail stand on flat surfaces. There are 2 small holes at the end of the tail cap for lanyard attachments.

If you're unfamiliar with any of the terms used in this review, click here for explanations on common flashlight related vocabulary.

The K1 provides decent output from the Q5 bin XR-E it uses. Beam profile has some ring shaped artifacts as expected from the use of a smooth reflector. Color tint with my sample is close to perfect white, perhaps leaning slightly to the cool side. The medium sized hot spot has a slightly skewed corona. The K1 is labeled as having 4 output modes in the following order, cycling through is done by half-pressing the switch..

Off > Medium (88 lumens) > Low (6 lumens) > High (107 lumens) > Strobe

As you can see, the medium and high levels are pretty close in terms of output intensity. In practical usage, there isn't much difference. The low levels are achieved by PWM (pulse width modulation) which is has a noticeable pulsing effect when waving the light around on the low level. Regulation is maintained very well and runtime is very good too, though regulation slightly struggles to maintain on high. A final thing to note is that the there is no memory feature so the light always start at the medium level from off.

The Good - Fit and finish are well done. Feels comfortable in hand. Good regulation and runtime.

The Bad - Slightly heavier than other single AA powered lights due to its thicker body wall and stainless steel head. Not much practical difference between the medium and high levels.

The Relative - Beam color temperature is almost perfectly white. Uses PWM for lower levels with noticeable pulsing on the low level. Able to tail stand. Uses a reverse push button switch. No memory feature.

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).