Brinyte PT28

Brinyte PT28 Oathkeeper review

Brinyte PT28 Oathkeeper specifications

Brand / ModelBrinyte PT28 Oathkeeper
Lumens1600 Lumens
Beam intensity15200 cd
Battery config.1*18650 / 2*CR123A
BlinkiesStrobe / SOS
Review dateJuly 2020


The Brinyte PT28 Oathkeeper is intended to be a tactical flashlight. This is evidenced by the patented (and removable) tactical grip ring and the use of a rear momentary switch. The PT28 has some stand-out features such as magnetic charging, good current regulation, and a dual-switch setup.

Brinyte isn’t afraid to try unique designs (check out the B21 Complex!) and they also make my favorite zoomie (the B158 / B158B), so I was curious to see what they cooked up with the PT28 Oathkeeper. Plus, this new Desert Tan color is beautiful.

What you’ll get:

The PT28 arrived in a rather plain-looking cardboard box with “PT28” scrawled in ink pen on the side. Granted, this is a pre-release light and so the final packaging may not be ready yet as of the time of this writing. The light was well protected, slipped into a bubble-wrap sleeve and then sandwiched between two sheets of egg-crate foam.

  • Holster
  • Battery
  • Charging cable
  • Paracord lanyard
  • “BR” Tactical ring
  • Clip
  • Manual
  • Spare o-rings

Handling of the Brinyte PT28

The first thing you notice when handling the Brinyte PT28 out of the box is the unique “BR” tactical ring.  Not to be confused with the cigar-grip rings that are relatively common, the patented tactical ring forms a large loop on the side of the flashlight.  It provides a quick way to get a very firm grip on the PT28 and assists with easily activating the rear switch in tactical situations.  The tactical ring has two keyways (and thus two different rotations that it can be affixed in).  It can easily be removed if desired by removing the tailcap and ring, then reinstalling the tailcap.

The pocket clip is nothing to rave about, but it is functional.  It is short and sturdy.  Certainly not deep-carry.  The provided lanyard is pretty nice, made of camo paracord with a lobster claw clasp.  Also included in the package is a holster that is tailored to the PT28.  It is stamped with the Brinyte branding.  There’s an elastic sleeve on the side for carrying a spare battery.  The bottom of the holster has a hole to expose the reflector.  The side is cut out to accommodate the tactical ring.  The top has another hole that exposes the switch.  The openings at the top and bottom allow the light to be activated while in the holster.

The tailcap is of the saddle style, which provides easy activation of the forward-clicky tail switch.  It also allows for tail standing, though it’s not terribly stable when doing so.  In addition to the tail switch, you’ll find an e-switch on the head for mode changes.

Build Quality, knurling, threads, and anodization

Upon opening the box of the Brinyte PT28, I was immediately impressed with the finish on the flashlight. The Desert Tan anodizing (HAIII) on the aluminum is smooth, even, and gorgeous looking. There is minimal knurling – a small section of square-shaped formations on the head, and if you remove the tactical ring, there are more of them around the tailcap. The body tube has the Brinyte logo set into it.

The head has non-aggressive crenelations. There are flat areas on opposing sides of the head. In addition to preventing the flashlight from rolling, they provide a location for the e-switch on one side and a magnetic charging port on the other.

The head and body tubes are glued together. This is likely due to Brinytes construction which uses a tube-within-a-tube construction for the body, akin to what you’d find on a FW3A. This tube style allows for the driver to constantly be active and aids with the built-in charging and side indicator light. This also necessitates the tail threads to be non-anodized, though they are well-formed and square cut.

LEDs, Lens, Bezel, and Reflector

On the business end, you’ll find a cool white Cree XHP35 HD (domed) emitter that is well centered in the smooth reflector that provides a nicely defined hotspot. This is surrounded by a lightly crenulated aluminum bezel that is part of the head.

Being a Cree XHP35 LED, there is minimal tint shift when compared to the newer flip-chip Cree LEDs such as the XHP35.2. Up close, there are few minor rings to the beam but they are not noticeable in typical use.


  • Length: 140.8mm (5.54”)
  • Head diameter:   26.5mm (1.04”)
  • Body diameter: 25.4mm (1.00”)


  • Without battery, without tactical ring: 110g (3.88oz)
  • Without battery, with tactical ring: 127g (4.48oz)
  • With battery and tactical ring: 175g (6.17oz)

Size comparison

Image 1: 2 Brinyte Tactical Flashlights: Left: Brinyte PT18Pro, right: Brinyte PT28

Image 2: from left to right: Brinyte PT18pro, Convoy C8, Wurkkos FC11, Convoy S2+, Brinyte PT28

Image 3: from top to bottom: Convoy S2+, Wukkos FC11, Brinyte PT28

Driver & User Interface:

The Brinyte PT28 Oathkeeper uses a well-regulated boost driver that accommodates either 1*18650 or 2*CR123A batteries.  It is a dual-switch configuration, but the driver is constantly powered.

Modes: there are four brightness levels (low, medium, high, and turbo) and two blinky modes (strobe and SOS)

From OFF (using the tail switch):

  • Half click: momentary on, last used mode
  • Double half click: momentary strobe
  • Single click: constant on, last used mode
  • Half click + full click: constant strobe
  • Single click while holding the e-switch: direct access to low mode

From ON:

  • Single click (tail switch): turn the light off
  • Single click (e-switch): change modes (cyclical, low > med > high > turbo)
  • Double click (e-switch): enter Strobe mode, another double click enters SOS mode.  Single click to return to last brightness mode

Mode memory:

  • Yes, mode memory is present (last used mode)

Low voltage warning:

  • The e-switch has an LED indicator in the center that indicates the battery level for 5 seconds when the flashlight is turned on.
  • Battery capacity 100-70%: constant green
  • Battery capacity 70-30%: constant orange
  • Battery capacity 30-10%: constant red
  • Battery capacity <10%: flashing red


  • Strobe and SOS are present.  From off, double click the tail switch to directly access strobe mode.  From on, double click the e-switch to access strobe mode.  While in strobe mode, a double click will take you to SOS mode.  A single click will exit blinky modes.

Lock-out mode:

  • No electronic lockout mode.  You can quarter-turn the tail cap for a physical lockout.


  • PWM is not visible in any mode

Additional info: the indicator LED will dimly glow green as a locator light while the PT28 is off.  This can be toggled ON/OFF by holding the e-switch for 10 seconds while the flashlight is on.  This is confirmed by a short blink of the main LED.

Batteries and charging:

The PT28 Oathkeeper ships with a Brinyte-branded, protected 3100mAh 18650 battery.  It also accepts 2*CR123A batteries.

The kit comes with a magnetic charging cord that plugs into a USB-A power port.  The magnetic end easily mates up to the charging pad on the side of the flashlight.  This style of charging helps with water resistance as you no longer have an opening on the side of the flashlight to contend with.

In my testing, charging terminated at 4.12 volts.  Additionally, you can turn on the PT28 in either low or medium mode while it is charging.  While charging, the indicator LED will glow constant red.  Once it is fully charged, the LED will turn green.  If something abnormal happens, the LED will turn orange.


For current measurements, a ANENG AN8008 multimeter and UNI-T UT210E clamp meter were used.  Lux was measured by a UNI-T UT383 BT at 5 meters.  Lumens were measured in a homemade lumen tube using a TSL2591 sensor, calibrated against a Wuben TO50R.

Amp measurement

  • Low: 29 mA
  • Med: 128 mA
  • High: 790 mA
  • Turbo: 6.5 A
  • Standby, indicator on: 144 uA
  • Standby, indicator off: 122 uA

Runtime graph

Runtime tested using the provided 3100mAh Brinyte battery, no cooling.  Test terminated at 2.84 volts.

Lumen measurements (for each mode)

  • Low: 12 lm (spec: 10 lm)
  • Medium: 63 lm (spec: 60 lm)
  • High: 342 lm (spec: 360 lm)
  • Turbo @ 0sec: 1705 lm
  • Turbo @ 30sec: 1636 lm (spec: 1600+ lm)

Throw numbers:

  • Lux at 5m: 712 lux
  • Candela: 17800 cd
  • Throw: 267 m (292 yds)


All beam shots are taken at 25m (82ft) using a Pixel 3 set to ISO 200 with ½ second exposure time

  • Brinyte PT28
  • Brinyte PT18pro
  • Convoy C8 with XP-L HI 3D at 3 amps
  • Sofirn SP33 V3
  • Brinyte PT28 (left) vs C8 (right)
  • Brinyte PT18pro (left) vs PT28 (right)

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

Overall conclusion


  1. Great overall build quality – design, anodizing, etc.
  2. Unique tactical ring
  3. Well regulated
  4. Built-in charging
  5. Direct access to low mode
  6. Included accessories (holster, lanyard, tactical ring)


  1. The UI doesn’t match its tactical marketing
  2. Unique charging cable
  3. Cold white LED with no options for other CCTs
Reviewer Gabriel
Author: Gabriel

Rating: 4 stars ★★★★

Overall, I really really like the Brinyte PT28 Oathkeeper. But Brinyte advertises this as a “tactical flashlight for military, law enforcement officers and outdoor sportsmen.” I feel like they really missed the boat on the UI when it comes to tactical applications. Sure, there’s direct access to strobe. But more importantly, would be direct access to turbo. When you need a lot of light and you need it now (military and law enforcement), that tail switch needs to activate turbo every time. Having it recall the last used mode means that instead of blinding an aggressor, you could be hitting him with a measly 10 lumens. I really like everything else about this light and I think it’s great for outdoorsmen. If they would update the UI to line up with the tactical branding, the Brinyte PT28 Oathkeeper would be a 5-star flashlight.

Brinyte PT28 for sale

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