Amutorch E4 Brass Flashlight Review

Amutorch E4 Brass Flashlight Review

Amutorch continues to make interesting flashlights, and the E4 Brass is right in line.  This tiny brass quad uses a 20350 cell and features a reverse clicky switch!

Amutorch E4 Brass Flashlight Official Specs and Features

Here’s a link to the Amutorch E4 Brass flashlight product page.


The Amutorch E4 Brass flashlight just has one body style, but there are two emitter options.  There’s a Nichia 219c available in 5000K, and a Luminus SST-20 in 6500K (seen here).


A full package of this Amutorch E4 Brass flashlight runs $41.97.  There are packages which cost less.  The “no charger” package comes in at $39.87.  This is the package I would recommend.  The “light only” package comes in at $34.97.

Short Review

This is a quirky little light.  I really like the host.  The build quality is on par with other Amutorch flashlights I’ve handled, and commensurate with the price.  I don’t care too much for the driver though – the mode spacing is not very good.  There’s no real “low” mode.  But as it’s a brass flashlight, I have to say I’m a fan!  (Especially at the price of $35 – I think when this was released it was much more.  So this is good.

Long Review of the Amutorch E4 Brass Flashlight

The Big Table

Amutorch E4 Brass Flashlight
Emitter: Luminus SST-20 (6500K)
Price in USD at publication time: $41.97
Cell: 1×20350
Turbo Runtime Graph High Runtime Graph
LVP? Yes
Switch Type: Mechanical
On-Board Charging? Yes
Charge Port Type: USB Charger
Charge Graph
Power off Charge Port
Claimed Lumens (lm) 4000
Measured Lumens (at 30s) 547 (13.7% of claim)^
Candela per Lumen 7.5
Claimed Throw (m)
Candela (Calculated) in cd (at 30s) 1457lux @ 3.56m = 18465cd
Throw (Calculated) (m) 271.8
All my Amutorch 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

what's included

  • Amutorch E4 Brass Flashlight
  • Amutorch 1400mAh 20350 cell
  • Charger (hard wired USB power)
  • Spare o-ring
  • Warranty card

Package and Manual

The box I got with this light looks just like a few other boxes I received from Amutorch.  It’s not labeled specifically for the Amutorch E4 Brass flashlight at all.

Also, I received no manual with the light.  I expect you would get a manual but… well I didn’t.

Amutorch E4 Brass Flashlight Build Quality and Disassembly

feature photo

The quality of the host here is quite good.  This is a raw brass flashlight and has raw brass features (ie the smell).  But it’s finished in such a way that the brass is smoothed off and not right in your face (or nose).

Overall the build quality is good though.  More on this later, but it’s a well-finished light.

Here’s the top-down view.

This light only unscrews at one place, as seen below.  The head comes off the body.  That’s how you’ll do cell swaps, too.  These threads are quite nice.  Not too long, square-cut, and quite smooth.  They’re brass threads, and so you have to expect that they’re smooth.

body threads

Inside these parts are springs – a real spring on the tail end, and a faux spring on the head.  While this is fine, I think many or most companies would use a brass button here.  But these faux springs seem to be Amutorch’s thing.  Anyway, it works fine, and as I said above – you should be buying the “with cell” package anyway, so you shouldn’t be needing a spring here for shorter cell support.

tailspring and head contact

I didn’t pull this apart, but this reverse clicky switch looks to be held in place by a brass retaining ring.  It should unscrew right out if you need to do switch maintenance.



Size and Comps

The only dimension stated officially is the length – 68.5mm.

Dimensions I measured:
Tail diameter: 28.02mm
Head diameter: 29.62mm
Body diameter (thinnest): 25.98mm
Inside cell tube: 21.75mm
Body length: 48.08mm
Head length: 28.38mm

Total: 68.48mm

Head: 62g
Body: 80g
Cell: 28g

Total: 168g

If the flashlight will headstand, I’ll show it here (usually the third photo).  If the flashlight 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 formats.

beside torchlab boss 35

Retention and Carry

Discussing the pocket clip brings me to one of my few issues with the Amutorch E4 Brass flashlight.  First of all, the pocket clip is of the “cheap” variety.  I can get over that; it’s not the end of the world.  I can even replace it with something else.

My issue, as you can see above, is that the pocket clip is crooked.  It’s not the “just nudge it back into place” type crooked either.  It seems to be crooked permanently.

Also included is a lanyard, which only attaches through the holes (2) on the pocket clip.  This will be a secure method of attachment since the clip is a screw-in clip.


in hand

Power and Runtime

Amutorch provides in the package what you’ll need for powering the Amutorch E4 Brass flashlight.  It’s a lithium-ion cell, in a very unusual size – 20350.  A single 18350 will work as well.

included 20350

This is a flat top cell, and I couldn’t tell you where to get a replacement (aside from Amutorch.)

The cell goes into the light in the usual orientation – positive end toward the head.

included 20350 installed

I won’t say the cell swims in the cell tube, but I bet a 21350 cell would fit too.  Which leaves open the door for a longer cell tube, and running 21700 cells.  I don’t even know if 21350 exists.  Either way, I’d love a longy tube for this guy – running 20700 cells or 21700 too.  (Also yes I confirmed that a 21700 cell does fit.)

included 20350 installed

Here are a few runtime graphs.  Amutorch states the turbo output to have a 30-second duration, so we’ll call it a “timed stepdown.”  But in my test, this high output didn’t last 30 seconds.  As a result, I read this as a “547 lumen light” on Turbo, despite the initial output being nearly 2900 lumens.  And yes, 2900 lumens is nowhere near the 4000-lumen claim.

runtime graph

In the graph above, I did reset the light to turbo a couple of times, including one well after the light had shut off for low voltage protection.  You can see toward the end of all these runs that the main emitters are flashing a low voltage warning before finally shutting off, too.

runtime graph

One of the things I like very little about this light is the mode spacing.  I immediately set my light to Group 5, which has 4 modes (plus turbo) and I have to say there’s really no reason to do so.  High and Medium are so close in output that it’s hard to even tell them apart.  These runtimes look good though, with flat output for the duration.

runtime graph

As stated above, the main emitters flash a low voltage warning, and then the light shuts off.


Included with the package (if you buy the package) is this charger.

included charger

This is a single-bay lithium-ion charger, and hard-wired to connect to USB power.

The charger is only suitable for lithium-ion cells (no NiMH!).

included charger

The one bay supports the 20350 cells just fine, of course.

included charger

Notably, though, there’s nothing chemically special about this 20350 – you can charge it in any bay charger that you’d also use for 18350 or 18650, with no issues at all.

I tested a couple of charge cycles with this charger.  This is only a broad picture, and not a “charger test” necessarily.  I logged from the USB source.

included charger charge graph

Modes and Currents

Mode Mode Claimed Output (lm) Claimed Runtime Measured Lumens Tailcap Amps
Turbo 4000/850 0.5m/43m 547
(2895 initial, though)
High 850 1h 574 1.50
Mid 350 1h42m 275 0.68
Low 180 3h32m 0.34
Eco 30 30h 0.04

Pulse Width Modulation

No PWM on any mode.

For reference, here’s a baseline shot, with all the room lights off and almost nothing hitting the sensor.  Also, here’s the light with the worst PWM I could find.  I’m adding multiple timescales, so it’ll be easier to compare to the test light.  Unfortunately, the PWM on this light is so bad that it doesn’t even work with my normal scale, with is 50 microseconds (50us).  10ms5ms2ms1ms0.5ms0.2ms.  In a display faster than 0.2ms or so, the on/off cycle is more than one screen, so it’d just (very incorrectly) look like a flat line.  I wrote more about this Ultrafire WF-602C flashlight and explained a little about PWM too.

User Interface and Operation

The Amutorch E4 Brass flashlight uses a mechanical tail switch.  In this case, it’s a reverse clicky.  The switch is very clicky, with positive action.  This ring around the switch does not impede clicking.

reverse clicky

There’s an unusual delay between the switch being fully clicked and actuation.  The switch seems to need to be fully in its rest state before the action happens.  That’s unusual in that you’re probably accustomed to being able to keep on the switch just a little while switching modes or whatever.  Not so, here.

reverse clicky

Here’s a UI table!

State Action Result
Off Click On (Mode Memory)
On Click Off
On Tap Mode Advance
On Tap 5x Group select (light blinks 1x, then 2x, 3x, 4x, 5x – click after the desired group)τ
On Double Tap Turbo
On Tap 3x Strobe
Strobe Tap Previous mode

τ The groups are as follows:
Group 1: 850lm
Group 2: 30lm-850lm
Group 3: 350lm-850lm
Group 4: 30lm-350lm-850lm
Group 5: 30lm-180lm-350lm-850lm

LED and Beam

In my review copy are four (aka “quad”) Luminus SST-20.  The claimed CCT is 6500K, and that seems about accurate.

quad emitters

Also available is a 5000K Nichia 219c, and that’s what I’d buy and recommend.  The Luminus will likely have higher output though, and according to the outputs we’ve seen above, that means the Nichia might be in the 2000 lumen range (or so) on turbo.

quad emitters

The bezel is smooth, so when headstanding no light escapes.  Also despite the bezel clearly being a screw-down bezel, I was unable to remove it.

quad emitters smooth bezel

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)

I keep the test flashlight on the left, and the BLF-348 reference flashlight on the right.

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


What I like

  • Nice brass light!
  • Fairly unique design
  • Complete package under $45
  • Also works with 18350
  • Should be very easy to modify

What I don’t like

  • Crooked clip
  • Mode spacing isn’t great
  • Weird delay between clicking and result
  • Charger is very slow
  • Timed stepdown


  • This light was provided by Amutorch for review. I was not paid to write this review.
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