HDS Rotary 170 Nichia 219B

Review: HDS EDC Rotary 170 219B


The EDC Rotary from HDS Systems is a compact Everyday Carry sized flashlight that features some of the most sophisticated electronics available in a handheld illumination tool.  Incorporating a tail-mounted switch and rotary brightness control, the HDS EDC Rotary allows users to select from 24 discrete output levels as well as Emergency and Tactical Strobe modes.  The advanced electronics also allow the end-user to customize several aspects of the light’s operation.  Following a recent price increase from the manufacturer, the EDC Rotary currently retails for about $279.

For the discerning flashlight user, OVEREADY has commissioned HDS Systems to produce a custom version of the EDC Rotary equipped with the Nichia 219B emitter, well known for its neutral tint and accurate color rendering.  When powered by a single 123A lithium primary or 16340 rechargeable battery, the Nichia 219B equipped Rotary is rated to produce 0.02 to 170 lumens of output. 

A sample of the custom HDS Rotary 170 219B with black stainless steel bezel and flat tailcap was provided by OVEREADY for this review.

Custom HDS EDC Rotary 170 – Overview

The EDC Rotary arrives in an HDS retail blister pack and includes a Duracell 123A lithium primary battery (already installed), quick reference card, and a very thorough and well-written User’s Guide.

HDS EDC Rotary 170 Nichia 219B

The head, body, and tail of the HDS EDC Rotary are constructed of aluminum with a Mil-Spec hard-anodized black finish and plentiful knurling for improved grip.  The blackened bezel is made of Stainless Steel with an AlTiN coating for added durability and wear resistance.

HDS Rotary 170 Nichia 219B

Where many lights have a thin bezel ring to protect the softer aluminum of the light body, the HDS EDC Rotary bezel is a substantial piece of stainless steel that actually surrounds much of the machined aluminum reflector assembly.  Thick Acme threads and an O-ring seal keep moisture and contaminants away from the LED and electronics.

HDS EDC Rotary 170 219B

The other end of the light is home to the tail mounted switch and rotary control.  The flush mounted switch has a smooth rubber boot and sits in a shallow depression in the tailcap.  The switch boot protrudes slightly beyond the end of the tailcap which makes tailstanding slightly unsteady.  A protruding tailcap switch is also available.

HDS EDC Rotary 170 219B

The distinctive rotary control allows the tailcap to rotate nearly a full 360 degrees and enables users to dial in the exact amount of light needed for a task before or after turning the light on.  A stainless steel screw provides a positive stop when the tailcap is turned fully in either direction.

HDS EDC Rotary 170

(Left) Lowest output setting, (Right) Highest output setting

The battery compartment is accessed by unscrewing the head from the body, with the large Acme threads engaging smoothly and solidly.  The light can be “locked out,” to prevent accidental activation, by loosening the head approximately 1/2 turn.

HDS EDC Rotary 170 219B

A look inside the head and body reveals nickel plated battery contacts and springs.  Dimples on the contacts provide increased contact force for a low resistance connection to the battery.  All electronics are potted for protection against vibration and shock.

Custom HDS EDC Rotary 170 – Operation

From the factory, the HDS EDC Rotary is programmed with 4 output modes, all of which are accessed with the tailcap switch.

From OFF

When the light is OFF, a single click and release of the switch will activate the output level selected via the rotary control.  This level can be chosen prior to pressing the tailcap button or adjusted any time after the light is on.  When looking at the rear of the light, turning the rotary control fully counter-clockwise will select the lowest output mode while rotating clockwise will select progressively higher levels.  Each subsequent level is roughly 1.5 times the brightness of the previous level.

HDS Rotary Brightness Levels

Image courtesy of HDS Systems

Alternatively, while the light is off, a quick click followed by a second press and hold of the tailcap button will activate constant-on output at the maximum output level, regardless of the setting on the rotary control.

While ON

Once the light is ON, the additional modes can be selected with various combinations of button presses.  Regardless of operating mode, a single click of the switch will always turn the light off.

Pressing and holding the tailcap button for 1 second will activate momentary maximum output for as long as the button is held.  Operation will return to the previous mode when the switch is released.

As when the light is off, a click followed by a press and hold of the tailcap button will activate constant-on output at the maximum level.

A double click of the tailcap button will toggle output between the rotary output mode and the Emergency Strobe, or the last of these modes to be used (when in Maximum or Tactical Strobe modes).

Triple clicking the tailcap button will activate the Tactical Strobe mode.

HDS EDC Rotary 170 219B

Locator Flash

A low power locator flash that produces a brief low intensity flash approximately once every three seconds is also available.  This feature may be activated, from OFF, by four quick clicks of the tailcap button.  The locator flash mode will remain active until it is turned off (with another four clicks from OFF) or until the light is reset.


Users wanting to take more control of the settings of their light may do so through the advanced customization features of the HDS EDC Rotary.  These settings include:

  • Turn on Preset – Enabled by default to use the level chosen with the rotary control.  If disabled, the light will remember the last mode used and return to that mode the next time the light is turned on.
  • Automatic Turn Off – Disabled by default.  When enabled, the flashlight will gradually turn itself off, dimming by one output level each second, if there is no activity for 10 minutes.  Clicking the tailcap button at any point during this sequence will return to the original output level and reset the 10 minute timer.
  • Locator Flash – Disabled by default.  Enabling this option sets the Locator Flash on by default.  The Locator Flash can still be disabled with four clicks from off, but it will reactivate following a reset.
  • Pseudo Momentary – Disabled by default.  When enabled, allows the tailcap button to be used like a true momentary switch when pressed and held from off.
  • Burst – Enabled by default to extend runtime.  Disabling this option will result in higher sustained output but a noticeable reduction in runtime.

Detailed instructions for setting these options can be found in the User’s Manual or online at the HDS Systems website.

Custom HDS EDC Rotary 170 – Performance

The machined aluminum reflector has a textured finish to produce a beam with a defined center hotspot that gradually tapers into the surrounding spill beam.  An ultra-clear glass window, with anti-reflective coating on both sides, helps ensure maximum light transmission.

HDS EDC Rotary 170 Nichia 219B

The main portion of the beam is completely free of artifacts and there is a slightly noticeable ring at the very edge of the spill beam.  The Nichia 219B emitter is absent the pinkish cast I have observed with the 219A and produces a very pleasing beam with good color rendition.  The beam tint appears very neutral and does not create the harsh contrasts created by some cool white LEDs.

The beam profile is somewhat narrower than some similarly sized lights making the EDC Rotary 170 219B appear more powerful than its rated output would indicate.

The following slides compare the custom HDS EDC Rotary 170 219B to a variety of other lights, all of them more powerful, to provide some perspective with regard to output, beam profile, and beam tint.  The beamshots can be compared across the full width of the image using the slider and additional comparisons can be accessed using the navigation buttons in the bottom-right corner of each image.

The following lights are shown for comparison:

  1. SureFire EB1 Backkup (Review)
  2. Elzetta Bravo with M60 Drop-in
  3. Elzetta Bravo with M60F Drop-in
  4. Malkof MDC (Review)
  5. SureFire E1D LED Defender (Review)
  6. Elzetta Alpha (Review)

Beamshots – 30 Yards to Swing

Beamshots – Garden


Custom HDS EDC Rotary 170 – Runtime

Production variance between LEDs, even of the same type or from the same reel, results in some being more efficient than others.  For most flashlight manufacturers this means that among a group of otherwise identical lights, some will be slightly brighter or dimmer than others.  Instead of following the same approach, HDS individually calibrates each and every light to produce exactly its rated output in lumens, regardless of any differences in efficiency.  Because of this, more efficient emitters will provide slightly greater runtime rather than increased output.  As a result, no single runtime test will be an exact representation of all HDS lights.

HDS EDC Rotary 170 219B

Tests were conducted using Battery Station lithium primary 123A and AW 16340 lithium-ion rechargeable batteries to measure the performance of this one sample of the Rotary 170 219B.  Two tests were run with each battery type, first with the Burst feature enabled and then disabled.

The Burst feature, which applies only to the Maximum output mode, automatically decreases output by one level 40 seconds after the switch is released.  This feature may be disabled through the light’s advanced customization options, resulting in higher sustained output at the expense of overall runtime.

Regardless of which modes or features are selected, the light will blink once and automatically drop to the next lower output level when the battery is unable to provide enough power to sustain the current level.  This process continues through the remaining levels until the battery is no longer able to maintain even the lowest level.  At this point, the light will begin to blink slowly at the lowest level until the battery is fully depleted.

HDS EDC Rotary runtime

With Burst enabled and powered by a single Battery Station 123A battery, the EDC Rotary reduced output after 40 seconds and maintained this lower level for over 1.5 hours before beginning further reductions in output.  After 2.5 hours output had dropped to the vicinity of 10 lumens.

With the Burst feature disabled, the light sustained its maximum output level for nearly 30 minutes before output began to decline.  Overall runtime was reduced by approximately 30%.

HDS EDC Rotary Runtime

Using an AW 16340 lithium-ion rechargeable battery achieved similar results, albeit with much shorter runtimes and steeper declines as the battery was depleted.

The overall output levels remained very consistent regardless of battery type.  Over the course of the tests, the EDC Rotary remained relatively cool, becoming only slightly warm to the touch when operated with the Burst feature disabled.

Custom HDS EDC Rotary 170 – Conclusions

Measuring only 3.7″ long and 1″ in diameter, the EDC Rotary 170 is small enough to be easily carried but large enough that it fills the hand well.  I have carried the light nearly every day since receiving it for review and have experienced no issues in operation or use.  Although the myriad of features and programming options may appear overwhelming, operation of the light couldn’t be simpler or more intuitive.

The rotary output control operates smoothly and consistently and truly allows the selection of the perfect level of light whether it is the 0.02 lumen lowest output, the 170 lumen maximum, or any of the 22 levels in between.  The control is easy to manipulate in both under and overhand grips but still has enough resistance that it won’t turn freely when carried in a pocket.  Of particular note to me is the fact that the Rotary is much easier to use in an overhand grip than other variable output lights that use a control ring near the head.

Although I was originally intimidated by the prospects of programming the Rotary, the exceptionally well written User’s Manual walked me through the process without issue.  The programming sequence did seem daunting at first but, for my part, that was because I was trying to absorb all the options at once.  After I decided what I wanted to do, it was fairly simple to enter the customization menu and make the desired changes, one at a time.  This is not something that will be done every day and I think many users will be completely satisfied with the default factory settings.

HDC EDC Rotary 170 219B

I’m easily distracted by all the neat features of the EDC Rotary but, at the end of the day, it’s how well it produces light that really matters.  In this regard, the 4500K Nichia 219B emitter chosen by OVEREADY appears to be an excellent pick.  I am a novice when it comes to commenting on things like beam tint and color rendering but this light has really opened my eyes to what is possible.  In some ways using this emitter in a flashlight has been like receiving my first set of eyeglasses.  Until I used it, I had no idea what I was missing.  The 219B emitter simply makes colors look more natural than any other light I have used.

The outstanding tint of the 219B does come at the expense of overall output but the Rotary 170 219B makes the most of its 170 lumens and produces a beam that is very useful at close and mid-range distances.  Overall runtime is very good and the elaborate regulation circuitry ensures users won’t find themselves suddenly without light as the battery is depleted.

Unfortunately the Rotary tailcap is incompatible with existing HDS pocket clips.  Also, the perfectly round design means the light is prone to rolling when laid on its side.  A clip specifically for the EDC Rotary is in development but, in the meantime, the only options are loose pocket carry, a holster, or some type of homemade lanyard.  The common 1″ diameter of the HDS EDC Rotary does allow it to be used with several accessories for similarly sized lights such as slip-on diffusers and filters.

This review represents two firsts for me, my first experience with an HDS light and my first experience with the Nichia 219B emitter, and I have struggled throughout trying to decide which superlatives to use in describing this Custom HDS EDC Rotary.  While many come to mind, they just seem inadequate considering the amount of thought, engineering, and refinement that have gone into producing the product I hold in my hand.  When viewed as a whole, the quality construction, thoughtful design, flexible user interface, useful output, and nice color rendering combine to create what feels like a precision instrument for creating light.  Perhaps that’s all that needs to be said.


  • Beautiful beam tint with the Nichia 219B emitter
  • Long regulated output with ample warning of battery depletion
  • Rotary control allows fine tuning output
  • Easy to use but allows advanced customization


  • Lack of pocket clip
  • Round design is prone to rolling
  • It’s a premium light at a premium price

For more information about the Custom HDS EDC Rotary with the Nichia 219B emitter, visit the OVEREADY website.  A “Clicky” (non-rotary) version with the 219B emitter is also available.

HDS flashlights are designed, built, and tested in Tucson, Arizona with some electronic components sourced from around the world.  All machined parts are manufactured in the USA and HDS products comply with the Buy American Act and are “Produced in the USA.”

The CR123A batteries used during runtime testing were provided by the fine folks at Battery Station.


Posted in Flashlight Reviews, HDS, OVEREADY and tagged , .


  1. Thank you for this review excellent Jim, I bought at Oveready the HDS Clicky LE, XP-G2 Cool – 250 lumens (black bezel), tailcap raised, UCL lens.

    The pocket clip is included.

    It is also my first flashlight HDS Systems. 🙂

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