The HDS Systems EDC Rotary is available in a number of configurations, and can even be custom-built based on your preference. The model reviewed here is the EDC-R1S-200 model. The head section of the Rotary is quite large relative to the entire light, in fact its length is about half that of the overall length. Up the front sits a solid and robust stainless steel bezel which protects the front end. It has a 6-point crenellation along its lip which allows for light to shine through when placed head-down. Branding and serial number are engraved along the outer surface of the bezel. I noticed that the bezel on my sample was slightly misaligned from the main head. Behind the bezel sits a thick, AR coated glass lens which is advertised as being shock mounted providing additional durability when subjected to impacts. The aluminum reflector has a rather fine textured surface, its nicely polished and texture is consistent and even. The LED sitting at the bottom of the reflector cup is well aligned. The rest of the head is made of aluminum and houses the electronics which are fully potted, meaning it's components are protected against shock and moisture. The "+" contact for the battery in mounted on a stiff spring mechanism which protects the battery from shock/impacts. Externally the head is totally finished with diamond textured knurling which provides excellent grip and coated in a very dark gray Type 3 anodizing. Threads on the inner surface of the head are cleanly cut and of the square threaded variety with no cross-threading or grinding issues.

The battery tube, which is also the main body makes up the second half of the Rotary and has the same knurled finishing as with the head and is also slightly narrower than the head which helps when held in a cigar grip. The dark gray colored anodized coating perfectly matches that of the head. The inside of the battery tube is anodized as well. The "-" contact is also mounted of a stiff spring, like the "+" contact. These hold the battery securely in place, reducing the chance of the light flickering off and on when the flashlights is subjected to impact. The Rotary has an electronic signal path integrated into the battery tube's wall which sends signals from the tail switch to the electronics in the head. A well-lubricated, thick rubber o-ting sits just below the threads which water proofs the battery tube. As denoted by the model number, this review sample comes with a flushed switch cap which allows the Rotary to tail stand. Although the rubber switch cap does marginally protrude out the tail end causing the light to wobble slightly. As the switch used is of the electronic toggle variety, mechanical feel and travel are substantially muted as compared to regular click switches. The switch can be programmed to work like a toggle switch or allow for momentary activation. The key feature of the Rotary is obviously the control ring/tail tail which allows output to be controlled by simple rotations of the tail end. It rotated all the way around, providing good spacing between each of the 24 distinct output levels. A tiny screw is installed which serves as a mechanical stopper, and also serves as a tactile indication for the minimum and maximum output levels.

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

The Rotary works pretty similarly to the earlier Ra Clicky model with 4 fully user-programmable output modes. The main difference is the addition of the rotary tail control ring. So in additional to the multiple click commands which allows the various mode selections, the Rotary includes an additional rotary mode which allows the user to quickly and directly vary output by simply turning the tail cap instead of having to resort to the multiple clicks as per the previous Ra Clicky model.

Out of the box, the Rotary comes with the following output modes set.
A: Level 24
B: Rotary Control
C: Level 16
D: Emergency Strobe

By default, the Rotary always switches on at output B, rotary control mode.
For the full user manual, please click here.

Other notable difference as compared to the Ra Click/Twisty include the different LED used. This change introduces some practical difference to current users of the Ra Lights. Firstly, beam tint is cooler compared to the more neutral tint of the former. Beam profile is also different, with the Rotary having a more diffused hotspot area. So even though total output is much higher on the Rotary, the Ra Lights throw a brighter hotspot. The final different isn't as noticeable the average user, this is the slightly noticeably PWM effect on the lower output levels on the Rotary. In the Ra Lights models, no discernible PWM effect is noticeable. Of course this doesn't make any practical difference in real work use.

As expected, the Rotary performs very well with runtime relative to output. Note that by default, the light has Burst mode enabled which causes the output to step down from Level 24 to Level 23 after 40 seconds. This features reduces the chance of overheating and is also intended to conserve battery life. Burst mode can be disabled, while inducing runtimes by about 30 minutes as compared to Level 23. Regardless of what output level you choose, the electronics will gracefully step down one level at a time as the battery runs down.

The Good - Rotary controls adds improved usability. Very rugged and durable, almost indestructible from general abuse. Regulation is well maintained and runtime is well above average. Allows additional customization if needed.

The Bad - Nothing significant.

The Relative - Beam tint has a slightly cool temperature. Is able to tail stand. Push button switch can be configured to allow momentary or toggle activation.