thrunite tt20 the outsider red 21700 flashlight on side

Thrunite has teamed up with The Outsider again to make a bigger version of the Thrunite TC15.  It’s not just bigger though; it has some massive changes.  The Thrunite TT20 The Outsider edition is available in red, uses a 21700 cell, and has a dual switch interface.  It also churns out the lumens!! Read on for more thoughts and testing.

Official Specs and Features

Here’s a link to the official product page.


There are two bodies available: black and red (seen here).  I believe the “The Outsider” edition is specifically the red, though.  Mentioned on the official page is a cool white emitter (seen here) and a neutral white emitter option.  But Thrunite says the NW isn’t actually available yet.


These are listed at $79.95, but a big coupon has brought these Thrunite TT20 “The Outsider” flashlights down to around $60.  (My opinion is at $60 this is a fantastic deal).

Short Review

Like I said above, at $60 this is a fantastic deal!  This light is a great performer, particularly on the High mode, where over 1300 lumens are sustained for well over an hour.  A cell is included – I’m not excited at all that it’s proprietary (and it’s everything bad a proprietary cell can be).  I will be excited to see the NW version, but overall the performance is great!

Long Review

The Big Table

Thrunite TT20 “The Outsider”
Emitter: Luminus SST-70 (CW)
Price in USD at publication time: $75.95
Cell: 1×21700
Turbo Runtime “Infinite” High Runtime
Switch Type: Dual
On-Board Charging? Yes
Charge Port Type: USB-C
Power off Charge Port with no cell?  No modes.
with cell?  No modes.
Claimed Lumens (lm) 2526
Measured Lumens (at 30s) 2684 (106.3% of claim)*
Candela per Lumen 8.5
Claimed Throw (m) 258
Candela (Calculated) in cd (at 30s) 760lux @ 5.903m = 26483cd
Throw (Calculated) (m) 325.5 (126.2% of claim)*
All my Thrunite reviews!
  • Measurement disclaimer:  I am an amateur flashlight reviewer.  I don’t have $10,000 or even $1,000 worth of testing equipment.  I test output and such in PVC tubes!!  Please consider claims within 10% of what I measure to be perfectly reasonable (accurate, even).

What’s Included

  • Thrunite TT20 The Outsider Red Flashlight
  • Thrunite 5000mAh 21700 – customized and proprietary
  • Charge cable (USB to USB-C)
  • Nylon pouch
  • Lanyard
  • Spare o-rings (2)
  • Spare charge port covers (2)
  • Spare tailcap switch cover
  • Manual and paperwork

Package and Manual

Build Quality and Disassembly

The Thrunite TT20 The Outsider edition flashlight is a well build solid light.  It’s not a small guy – but it’s a feature rich package that the size accommodates.

The red anodizing is on point here.  There’s a deep sheen to it that I really can’t recall on other lights.  There’s minimal branding, part of which is seen below and includes a serial number.

The grip is mostly around the body, but should help adequately prevent the light from slipping out of your hand.

The tailcap provides adequate reeding for cell removal.

The tailcap is protected enough to tailstand, and exposed enough to be used with gloves, and for side access.

The pocket clip will scar up the body a bit if you twist it around and move it.  I believe what you see here is the black from the clip rubbing off onto the body, not the red rubbing off to expose the underneath.

Here’s the other bit of branding.  This is the logo of The Outsider, who runs a youtube channel with over 600K subscribers!!

The threads are square cut, anodized, and smooth.

There’s a button spring in the tailcap.  You’ll also see two little divots in the aluminum – that’s for access to the switch, in case you need to replace the switch cover.  A spare is included.

The head has a spring too.  In fact take a good look down in there.  Unlike the Thrunite T2, which uses the exact same cell as this TT20, the TT20 requires the proprietary customized cell.  More on that later.

Size and Comps

Dimensions: 136mm*30mm *26mm
Weight: 98g (excluding battery).  180g with the included cell.

If a light will headstand, I’ll show it here (usually the third photo).  If a light will tailstand, I’ll show that here, too (usually the fourth photo).

Here’s the test light with the venerable Convoy S2+.  Mine’s a custom “baked” edition Nichia 219b triple.  A very nice 18650 light.

And here’s the light beside my custom engraved TorchLAB BOSS 35, an 18350 light.  I reviewed the aluminum version of that light in both 35 and 70 format.

Here are some of my other Thrunites!  The T2 seen below uses the same cell as in this TT20 The Outsider.

And here’s just a couple other randoms I had out….

Retention and Carry

Probably the main choice for carry of this light will be the nylon pouch.  It’s a standard pouch, and the light will fit into the pouch either orientation.  The top and bottom are closed, so no using this light in the pouch.

Also included (and attached from the factory) is this two-way friction fit pocket clip.

You probably know my distaste for this type clip, but this one isn’t so bad.  It’ll also fit on the tail end of the TT20, providing a fairly deep, bezel-down carry.  Since this clip is reversible, I see no good reason for the two-way clip.

There’s also a lanyard included, which attaches through two holes in the tailcap.  Both sides have holes.

The Thrunite TT20 will tailstand, too.

Power and Runtime

As stated above, the Thrunite TT20 The Outsider flashlight is powered by a single lithium ion cell.  The required cell is included.  It’s this 5000mAh Thrunite branded customized and proprietary 21700 cell.

The first bit of customized is that both positive and negative terminals are exposed on the positive end.  This is a requirement (full stop), because as you’ve seen above, the head end has the contacts for both, and both are required there for this light to operate.  (Period.)  (I state this specifically because the Thrunite T2 uses the same cell but doesn’t have both contacts on the head end, and regular 21700 cells will work.)

And here’s the bit of proprietary.  Yes other companies sometimes shroud the positive terminal with plastic, but this one seems thick and aggressive.  Some users report ability to charge this cell in their bay style charger – I couldn’t find one here that worked.  (Point is that they exist, and it can work, but unless you’re buying the charger specifically for that feature, don’t really count on your charger supporting this cell.)

All of this information means that this is the only cell that can be used in the Thrunite TT20 The Outsider.  Only cell that can power it.  Only cell that can be charged in it.  This is not a good feature….

The cell fits into the light in the normal direction – positive terminal toward the head.  The fit is very specific too.  There isn’t any extra room.  That means no rattle at all but also means you might have to shake the light a bit to get the cell out.  Then again you may choose to never take the cell out, since its full life can be lived inside the light itself.

Here are a couple of runtimes.  Turbo steps down quickly, but boy does it toast some lumens.  For a light this size, I’m very surprised that it holds ~2500 lumens for 1.5 minutes.  That’s really incredible.  After this the stepdown is dramatic, to around 650 lumens.

The High output (by which I mean “Infinite” High) is actually driven harder than Turbo, and so the runtime is shorter – only around 93 minutes.  But that’s at over 1300 lumens for over an hour.  Again, incredible in a tube light!!  There isn’t that much mass here, so yes the light gets warm, but this is very nice performance indeed.

The switch will tell when the cell is getting low, as follows:

Battery capacity: >20%, Blue light will be ON.
Battery capacity: 11%-20%, Red light will be ON.
Battery capacity: 1%-10%, Red light will flash and remind to charge the battery immediately.

Note: the battery capacity indicator will not work at Firefly mode, or when the battery capacity is 0%.

Also included with the Thrunite TT20 The Outsider is a charge cable.  It’s USB to USB-C.

The charge port is on the head of the light, opposite the e-switch.  There’s a press-in cover, which fits very securely.

This cover has a nice little tab, which really helps with opening.

USB-C to USB-C does work at 5V.

Here’s a charge graph of a couple cycles.  Charging is very consistent, and peaks at well over 2A.  Full charge takes just over 3 hours.

During charging, the indicating switch is red.  Once fully charged, the indicating switch is blue.

Modes and Currents

Mode Mode Claimed Output (lm) Claimed Runtime Measured Lumens Tailcap Amps
Turbo 2526/610 150s/237m 2684 9.40
Infinite High 1468/654 190s/235m 1450 3.11
Infinite Low 31 90h 30 0.06
Firefly 0.54 64d 0.01

Pulse Width Modulation

For reference, here’s a baseline shot, with all the room lights off and almost nothing hitting the sensor.  And here’s the worst PWM light I have ever owned.  Also one of the very first lights I ordered directly from China!

User Interface and Operation

There are two switches on the Thrunite TT20 The Outsider.  First is a tailcap forward mechanical switch.

And next is an indicating side e-switch.  This switch has a plastic cover, with a translucent dot in the center revealing blue/red emitters when needed.

This is a ramping light, with shortcuts to Firefly and Turbo.  The UI is good, but the memory function is one I tired of just a bit.

Here’s a UI table! The UI is exactly the same as on many other Thrunites with this switch, including the TN42!

State Action Result
Off Hold Side Switch (SS) Firefly
Off Click SS On (Mode Memory except Turbo/Firefly/Strobe)
Any Double click SS Turbo
Firefly Hold Lockout (red indicator when SS clicked)
Lockout Hold Unlock to Firefly
Lockout Click Tail Switch (TS) Double Lockout (red indicator always on)
Double Lockout Click TS then hold SS Unlock to Firefly
On Hold SS Ramp from low to high and back.  Double blink at highest and lowest.
Any Click TS Turbo
Any Tap TS Momentary Turbo (off upon release)
Any Click SS 3x Strobe

This is a good UI, except the mode memory.  Since Firefly is so low, and memory could mean you turn the light on in “infinite high”, it’s hard to achieve a low output upon startup.  It should be this:  Hold for firefly then ramp upon holding from Firefly (even if there’s a jump from Firefly to “infinite low”).  This means I more heavily control the ramp, and I can always start the ramp in low if I wish.  But that’s not how they made it.

Also it’s tucked away in the table above but be sure you note: the tail switch overrides anything.  Any click of the tailswitch is definitely always turbo.  Then off.

LED and Beam

The emitter of choice in the Thrunite TT20 is a Luminus SST-70.  My spreadsheet tells me this is the very first SST-70 I have ever played with and memory confirms that.  This is a nice little emitter, and benefits from the smooth reflector.

My review copy is cool white, though the product page makes rumor of a NW version.  I confirmed with the SST-70 datasheet that such an emitter exists in theory, all the way down to a temperature of 4500K.

The shots below are bookended by the specific outputs.  Firefly, Infinite low, then some random outputs, then Infinite High, then Turbo.

These beamshots are always with the following settings:  f8, ISO100, 0.3s shutter, and manual 5000K exposure.

Tint vs BLF-348 ( 219b version) (affiliate link)

Test light is on the left!  The shots below are bookended by the specific outputs.  Firefly, Infinite low, then some random outputs, then Infinite High, then Turbo.

I compare everything to the 219b BLF-348, because it’s inexpensive and has the best tint!


What I like

  • Complete package light
  • Neat branding with The Outsider
  • Dual switch interface allows fairly easy access to firefly, and very easy access to Turbo
  • Indicating switch is useful
  • Uses USB-C recharging!
  • Quite fast charging too, at >2A!
  • Performance (especially on High) is really outstanding
  • Doesn’t use PWM

What I don’t like

  • Customized proprietary 21700 cell
  • Two-way pocket clip
  • Mode memory problematic when you want “low” and it starts on “infinite high” and you have to ramp all the way down


  • This light was provided by Thrunite for review. I was not paid to write this review.
  • This content originally appeared at  Please visit there for the best experience!
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