The head of the H20 is protected by a smooth stainless steel bezel which protects the head from impact and damage. It's adhered to the head and not removable. Behind the bezel sits an ultra-clear glass lens which provides good light transmission. A rubber o-ring provides a seal between the lens and the fine-textured metal reflector. The alignment between reflector and LED sitting at the bottom is perfect by visual inspection. Externally the head is slightly tapered to the rear with an overall smooth and clean design. The threads are straight cut with right angled edges instead of the smoother, more common type with rounded edges. A rubber o-ring sits snugly just above the threads providing a good seal. Viewed from the rear we can see part of the PCB and the "+" contact for the battery. The "+" contact is raised, and as such both older flat-topped, and current button-topped 18650 cells can be used without problems.

Majority of the battery tube is machined with a knurling that's quite different from the common diamond or checkered texture which have been used in almost all lights reviewed so far. Instead the H20 has a bi-directional corkscrew knurling design, with a single flat face machined on where the branding is printed. It feels smooth when gripped around the battery tube, but provides good friction and grip length-wise. There's a hexagonal, nut-shaped design design at the front but it isn't meant to work as an anti-roll feature, more of a design choice for grip. Threads on the tail end, like those on the head, also have the square-cut design. They are anodized which means that the light can be locked-out when the tail cap is loosened. Another o-ring sits at the tail end for seal as well. The tail cap design seems to be influence by that of a torpedo fins. These machined extrusions also work as an anti-roll feature and helps when held in a cigar-style grip as well. There's a crenellated stainless steel strike bezel at the end of the tail cap so you wont have to worry as much about damaging the glass when using it to strike. There's also a small hole on the crenellated bezel for lanyard attachments. A forward push button switch is houses in the tail cap which allows for momentary activation. The tension from the switch is average, clicking and tactile feedback is very positive. The rubber switch cap has a checkered texture and sits recesses within the tail cap so the light can tail stand without problems. The entire light is consistently coated in a dark gray, Type 3 anodizing with no blemishes or other flaws to be found.

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

The Hermes H20 provides a narrow well-focused spot and has an almost perfectly white color temperature. There's a bright corona right around the hotspot and dark ring-shaped artifacts as common in most XR-E, though they aren't as bad as in some other lights. The H20 can be powered by a wide range of battery types including 16340, 18650 and CR123 cells.

The light can work as a simple high/low interface by either tightening or loosening the head, and it also provides programmable functionality. When the head is in the tightened position, output is set fixed at maximum brightness. The loosened head position can be programmed to any brightness level or strobe/S.O.S. function. By tapping (half-pressing) the switch twice and holding on the third tap, the light goes into the settings menu.

Activating brightness ramping.
The ramping always starts from minimum brightness, up to maximum brightness. As a reminder, the light blinks twice at minimum brightness, twice again at 50% brightness, and thrice at maximum brightness. When the 100% brightness level is reached, it cycles back from minimum brightness. Switch off the light for at least 2 seconds at the desired brightness levels and it will be set. No effects of PWM was noticeable even at the lowest brightness level. There was also no high frequency noise.

Activating strobe modes selection.
While in the brightness ramping mode, tap the switch once. The light will cycle through all the available strobe modes in the following order. As with the brightness ramping, the sequence is cyclical. Switch off the light for at least 2 seconds at the desired strobe mode. Switch off the light for at least 2 seconds at the desired brightness levels and it will be set.

Ramps from 1Hz to 15Hz > Beacon > Double Blink > 100% S.O.S. > 5% S.O.S.

Reset settings.
While in the Strobe selection mode, tap the switch once. The light will turn off although the switch is clicked on. Now, turn off the light for at least 2 seconds.

Although regulation dims as the battery is run down, overall runtime is actually very good and has a very similar pattern as that of the Fenix TK11.

The Good - Very good fit and finish, from the perfectly aligned emitter to the smooth overall anodizing. Comfortable ergonomics. Nice touches like the stainless steel head and tail bezels. Very good runtime from a 18650 cell.

The Bad - Regulation could be better.

The Relative - An almost perfectly white color tint. Is able to tail stand. Uses a forward push button switch.

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).