Streamlight ProTac Rail Mount HL-X Pro

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Streamlight ProTac HL-X Pro review

Streamlight ProTac Rail Mount HL-X Pro specifications

Brand & ModelStreamlight ProTac Rail Mount HL-X Pro
Flashlight categoryWeapon mount light (WML)
LEDLuminus SFT-40
Max. output1,000 lumens
Max. beam distance447 meters
Max. beam intensity50,000 cd
Battery config.1x 18650 / 2x CR123A
Onboard chargingNo (on battery)
Main modes2
Review publication dateMay 2024

Review intro:

When I was a kid, Maglite seemed to be THE brand of flashlights. They were tried and true, rugged, American, and popular. I took one with me camping when I went about once a month. Then I saw a camping leader of mine with a Streamlight Stinger. Game Changer! I loved my Maglites, but even decades later, I distinctly remember seeing a Streamlight for the first time. Ever since that time, I’ve seen trusted professionals using Streamlights

Until this point, I’ve never owned a Streamlight for myself. Recently, though, I’ve been on the lookout for a solid weapon-mount light for a long gun. I first checked out the Olight Odin GL Mini, which was pretty nice. I wanted to explore more options, though, and that brings us to the Streamlight ProTac Rail Mount HL-X Pro flashlight. Yes, that’s definitely a mouthful (if I just say “HL-X”, ya’ll will know what I mean, right?). It’s also a robust, purpose-built flashlight that aligns really well with what I was looking for.

To get up and going with this Streamlight, open up that package and insert the battery into the flashlight. Unlike many battery-included flashlights, the cell ships outside of the flashlight with this one – probably because the clear packaging is trying to show off that a rechargeable battery is included.

What’s in the package

The Streamlight ProTac Rail Mount HL-X Pro USB arrived in a clear plastic container that would go perfectly on a store’s display rack. I’m sure it actually is on several display racks. The clear plastic helps to show off the flashlight and its rechargeable battery. Unlike many flashlights that are seemingly stuck in a specs/numbers war, the HL-X’s packaging doesn’t highlight many specs besides to say that it puts out 1,000 lumens. The rest of the focus is on the included accessories and fitment. In the box was quite a lot, including:

  • Streamlight ProTac Rail Mount HL-X Pro
  • Battery
  • Micro USB cable
  • Remote pressure pad
  • Pressure pad attachment clips
  • Adhesive strip for the pressure pad
  • 1913 rail mount (pre-installed)
  • M-LOK rail mount
  • Allen (hex) keys
  • Various bolts/nuts
  • Zip ties
  • Manual

Flashlight in use, Build Quality, and Warranty

While you could theoretically use the Rail Mount HL-X as an ordinary flashlight, it is purpose built for using on a long gun – typically something like a MSR (modern sporting rifle). The HL-X comes with a 1913 (Picatinny) rail adapter pre-installed. This adapter is easy to use and allows the Streamlight to be quickly installed and removed, thanks to the large thumb-wheel for a nut. The rifle that I mounted the HL-X on had a M-LOK handguard, so I switched over to that adapter. You can orient the M-LOK adapter to slant either way, depending on where you want to mount it to your firearm.

The HL-X can be used on its own while mounted to the firearm, but it features something that Streamlight calls a Jack-Cap. That indicates that the tailcap has a covered port where you can just plug in a remote pressure pad – no need to remove the tailcap and install a special one for the pressure pad. Not only is that convenient, but it means that you also retain full functionality of the HL-X’s tail switch, even while you have the pressure pad installed. The pressure pad can be affixed to the firearm in several ways: 1913 clips, zip ties, and/or adhesive pad. I went the route of just zip-tying the pad onto my rail.

There is one switch on the HL-X: a forward-clicky tail switch. It’s very straight-foward to use, and provides silent momentary activation. There are two styles of pressure pads from Streamlight that can be used with this flashlight. The one that was included with my unit (you can buy these with or without a pressure pad) is a momentary-only pad. Streamlight also sells a latching pressure pad.

The Streamlight HL-X feels extremely well built. After getting the M-LOK mount installed and putting this on my firearm, the whole thing felt rock solid. There was no play whatsoever in the mount. To me, the only downside of the M-LOK mount is that it isn’t quickly removable like the 1913 mount is. Not that you’d need to be reinstalling the Streamlight all the time, but something worth pointing out.

Warranty? You betcha. Streamlight stands behind their products for life:

Streamlight warrants this product to be free of defects for a lifetime of use except for batteries and bulbs, abuse and normal wear. We will repair, replace or refund the purchase price of this product should we determine it to be defective. This limited lifetime warranty also excludes rechargeable batteries, chargers, switches and electronics which have a 2 year warranty with proof of purchase.

LED, Lens, Bezel, Beam, and Reflector

In my opinion, if you want both brightness and intensity, there are few better LEDs than what Streamlight chose: the Luminus SFT40. I don’t think that Streamlight actually ever said what LED that they used, but the looks of the emitter are unmistakable. The SFT40 produces a high-intensity beam with little to no tint-shift. Sure, it isn’t high CRI and doesn’t have a rosy tint. But this is a work tool, something you may be using to help protect the life of yourself and those around you – not really a time to be worried about DUV.

The LED sits in the middle of a smooth reflector. The arrangement is protected by glass, but not just any glass. Streamlight says that it’s high-temperature, shock-mounted, AR coated, impact-resistant BOROFLOAT® glass. That all sounds good, especially the shock-mount and impact-resistant parts. Because if you use the HL-X for what it’s designed for, there’s going to be a lot of shock involved.

Spectral measurements: 

I used the Opple Light Master to measure the flashlight at 5 meters distance. 

Mode:CCT:CRI Ra:duv
High6105 K68.2+0.0043

Dimensions and its competition


Length141 mm5.6 in
Head diameter37 mm1.4 in
Body diameter22 mm0.9 in

Dimensions are rounded to the nearest millimeter and the nearest tenth of an Inch.


WeightWeight in gramsWeight in oz
Without battery:(with M-LOK mount)151 g5.3 oz
With battery (with M-LOK mount)197 g6.9 oz

Weight is rounded to the nearest gram and tenth of an Oz.

Flashlight size comparison with its competition:

Group 1: Streamlight ProTac Rail Mount HL-X Pro, Olight Odin GL Mini

Group 2: Nitecore P20iX, Streamlight ProTac Rail Mount HL-X Pro, Fenix PD36R V2.0

Streamlight ProTac Rail Mount HL-X Pro : User Interface and Driver

This Streamlight is quite simple to operate, having just a single forward-clicky switch. However, it features their TEN-TAP programming functionality, which gives you the choice of 3 basic UIs depending on how you plan on using the flashlight.

Available modes: 

  • High, Low

Available blinky modes:

  • Strobe

Default UI, TEN-TAP Option #1: High/Strobe

From OFF:

  • Press and hold: momentary High
  • Single click: High continous
  • Press and click: Strobe .

From ON:

  • 1 click: Off

Mode memory:

  • N/A


  • To High: single click
  • To Strobe: press and click

Default UI, TEN-TAP Option #2: High Only

From OFF:

  • Press and hold: momentary High
  • Single click: High

From ON:

  • 1 click: Off

Mode memory:

  • N/A


  • To High: single click

Default UI, TEN-TAP Option #3: Low/High

From OFF:

  • Press and hold: momentary Low
  • Single click: Low continous
  • Press and click: High continous

From ON:

  • 1 click: Off

Mode memory:

  • N/A


  • To Low: single click
  • To High: press and click

Low voltage warning/protection:

  • None (besides decreased output)


  • Strobe, available by press+click while in UI #1

Lock-out mode: 

  • N/A


  • None detected

Additional/summary info on the UI: 

  • I really appreciate what Streamlight did with the TEN-TAP UI selection. For my uses, I really don’t want to mess with Strobe (or the flashlight coming on in Low), so I swapped to UI #2: High only and it’s perfect for my intended use.

Charging and batteries

The Streamlight HL-X kit that I received came with a Streamlight-branded SL-B26 battery. That’s a 2600 mAh 18650 cell with a Micro-USB charging circuit. Yes, you read that right – it’s Micro-USB in the year 2024. Technically there’s nothing wrong with Micro-USB, but I wish it would just fade into the history books at this point. Also, it took quite a while to charge the battery with the built-in port. It works fine… just slow. You could always pop it into a desktop charger if availab.e

The flashlight is also compatible with 2x CR123A batteries, which is a nice option in a pinch (or if your employer provides them).

Charge typeFitsNo fitCharge time
Battery with onboard Micro-USBButton-top 18650, 2x CR123AFlat-top 186505h 41min

Performance test

Lumen measurements

How Lumens are Measured: Understanding ANSI FL1 Standards How Lumens are Measured: Understanding ANSI FL1 Standards: The ANSI FL1 standards specify that output in lumens should be measured 30 seconds after turning on, as this is the standardized time for measuring brightness according to the industry standard. This is why we focus on this part in our measurements. The ANSI FL1 standards require an ambient temperature of 22 ± 3°C. We record the ambient the ambient temperature to identify potential reasons for any observed discrepancies.

Lux was measured by a UNI-T UT383 BT at 5 meters. Lumens were measured in a homemade lumen tube using a VEML7700 sensor, calibrated with a calibration light provided by 1Lumen. The included 46950 battery was used in the tests.

ModeAmps at startSpecifiedTurn on30 sec.10 min.
Low106 mA60 lm58 lm58 lm58 lm
High3.0 A1,000 lm1,300 lm1,274 lm817 lm
High at 3.6V3.3 A1,210 lm

Ambient temperature during testing:

  • 21 °C

Parasitic drain:

  • N/A – clicky switch

The output of the Streamlight HL-X exceeded expectations by a pretty good margin. Output does steadily drop as soon as you turn the light on, but it is very gradual and not noticeable to the eye. At 9 minutes in, the output flattens out and runs pretty steady after that.

Low mode was right inline with spec and stayed consistent throughout its entire runtime.

Streamlight ProTac Rail Mount HL-X Pro Battery Life: Runtime graphs

How Runtimes are Measured: Understanding ANSI FL1 Standards About ANSI FL1 runtime standards: The runtime is measured until the light drops to 10% of its initial output (30 seconds after turning on). This does not mean that the flashlight is not usable anymore. The last column shows how long the light actually works till it shuts off. If there is a + symbol, it means that the test was stopped at that particular point, but the light was actually still running. This happens on certain occasions, with certain drivers, firmware, or batteries.
ModeSpecifiedRuntime (ANSI FL1)Time till shut off
Low24h 0min25h 06min26h 00min+
High1h 45min1h 43min3h 03min+

My tested runtimes were very close to Streamlight’s claims. Note, that after dropping down, the light continued to run at <2 lumens for quite some time.

I recently reviewed the Olight Odin GL Mini – another weapon-mount light for long guns. It does have a bit smaller battery (about 22% less capacity), but it does have a green laser baked in – so that’s a nice perk. When compared, the Streamlight drops output at a much slower pace than the Olight, and it doesn’t drop as steep. Oh, and runtime is a good bit longer. Overall, the performance of the Streamlight seems quite a bit better (at least in graphical form).

streamlight protac rm hlx pro runtime comp

Peak beam intensity and beam distance measurements

About Peak beam intensity: Understanding ANSI FL1 Standards About peak beam intensity The calculated value of distance in meters at which the flashlight produces a light intensity of 0.25 lux. (0.25 lux is about the brightness of a full moon shining on an object). This means that the intensity has decreased so much, it becomes difficult to see darker objects, or objects that don’t reflect light. The columns ‘Meters’ and ‘Yards’ use rounded numbers.

Intensity was measured at 5 meters after being turned on for 30 seconds. A UNI-T UT383 BT lux meter was used.

ModeSpecifiedCandela measured MetersYards
Low3,100 cd2,850 cd107 m117 yd
High50,000 cd51,925 cd456 m498 yd

Ambient temperature:

  • 21 °C 

Much like the other specs (aside from High’s lumens overperforming), the beam intensity teams were very close to expectations. Great!


Camera settings and distance: Beam shots of the building are taken at 30 m (33 yd) using a Canon EOS R100 with a lens set to 18mm. Manual settings: ISO 800, 1/4sec, F4.5, 5000K.

Beamshots of the following flashlights compared:

  • Streamlight ProTac Rail Mount HL-X Pro
  • Olight Odin GL Mini
  • Powertac Warrior LT G5

Please note that the following beamshots are mainly intended to showcase the beam pattern and beam quality, rather than overall performance. These images are typically taken directly after activation, and in different seasons or weather conditions, and therefore do not fully represent its overall performance. For accurate performance metrics, such as output, beam distance, and runtimes, you need to look at the performance section of this review.

Disclaimer: This flashlight was sent to us for review at no cost by Streamlight. We have not been paid to review, nor have we been holding back on problems or defects.

Final Verdict


  1. Rugged build quality
  2. Legendary dependability
  3. Full kit with battery, pressure pad, and multiple mounting options
  4. TEN-TAP UI with 3 simple UI choices
  5. Jack-Cap – can use pressure pad and tail switch simultaneously
  6. Accepts 18650 or 2x CR123A


  1. Micro-USB charging
  2. Some rings in the beam

Explanation on star ratings:

1: Avoid: a match would be a better choice – 2: Poor: significant defect or issues; almost unusable – 3: Average: some defects or issues; but still usable 4: Good: recommended (minor issues) – 5: Great: highly recommended

Reviewer Gabriel

5 stars: ★★★★★

While our star rating provides a reliable indicator, we encourage you to read the full review to make an informed decision based on your own needs and preferences.

If you have a tool that you’re trusting your life to, such as a rifle that may be used in a defensive situation, it needs to work every single time, and it needs to be easy to use. Streamlight has been designing products that fit the bill, and the ProTac Rail Mount HL-X Pro (USB) is no exception. It’s rugged, easy to use, and if it follows Streamlight’s renowned dependability – it is something that you can trust in such a situation.

This kit comes with every accessory that you’ll need to outfit your firearm. There’s the (Micro-USB charging) battery, of course, but also a great pressure pad with multiple mounting options. And the HL-X can be mounted to either Picatinny or M-LOK rails. I mounted the HL-X on an M-LOK handguard and it was rock solid.

If you’re looking for a dependable weapon-mount light for a long gun, the Streamlight ProTac Rail Mount HL-X Pro is as good as its name is long!

Buy your Streamlight ProTac HL-X Pro here

1lumen selects and reviews products personally. We may earn affiliate commissions through our links, which help support our testing.