Today I have a little full-metal keychain light by Fenix.  It’s the E03R, and it’s a dual emitter red/white light with USB-C charging and an indicating e-switch.  Read on for some testing and thoughts!

Official Specs and Features

Here’s a link to the official product page.


There’s only one version of the E03R.


These list for $37.00, have been marked down to $26.95, and street price is more like $24.95 at nealsgadgets! (referral link)

Short Review

I like this light a lot.  The red could use levels (other than on and strobe).  Switch is good, charging is good…. It’s a very sleek light too, which makes it fun to use.

Long Review

The Big Table

Fenix E03R
Emitter: Match CA18 (white) (Everlight 2835 (red))
Price in USD at publication time: $24.95 at (referral link)
Cell: Internal
High Runtime Medium Runtime
LVP? Warning
Switch Type: E-Switch
Quiescent Current (A): ?
On-Board Charging? Yes
Charge Port Type: USB-C
Power off Charge Port with no Cell? Two low white and both red
Claimed Lumens (lm) 260
Measured Lumens (at 30s) 231 (88.8% of claim)*
Candela per Lumen 3.2
Claimed Throw (m) 42
Candela (Calculated) in cd (at 30s) 62lux @ 3.643m = 823cd
Throw (Calculated) (m) 57.4 (136.7% of claim)*
All my Fenix 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

  • Fenix E03R Keychain Flashlight
  • Split ring
  • Manual and other papers

Package and Manual

Build Quality and Disassembly

This is a bit of an unusual built light – it seems to be a “unibody” design with all the guts stuffed in from the front.  The build quality is very good, but I’d say the ability to disassemble this light is very low.

I’m not sure if this is a permanent installation dual optic but if you wish to remove it do so carefully, since finding a replacement will probably be difficult.

There are no seams anywhere on the body.

The switch and charge port are the only two holes in the body.

Size and Comps

Length: 1.85” (47mm)
Width: 0.94” (24mm)
Height: 0.47” (12mm)

Weight: 0.78 oz. (22g) including battery

This Nitecore TINI is the closest in size that I could think of.  The Fenix is (again) a single piece of metal, which I’d say is a nice feature over the TINI.

Retention and Carry

All that’s really included for carrying the E03R is a tiny split ring which attaches to the tail loop.  Through that split ring you could attach keys or a lanyard or whatever.  There is no pocket clip and no magnet.

Power and Runtime

The E03R is powered by an internal 200mAh LiPO cell, which is not serviceable.  I do not know (but doubt) that Fenix offers a replacement service for these batteries.

There’s an indicating switch which can be activated without turning on the light.  Just click the switch (when off) and the switch will indicate in this way:
Green: >70% power
Green flashing: 40%-70% power
Red: 10%-40% power
Red flashing: <10% power

Power is also indicated every time the light is turned on.

Here are a few runtimes.  “High” is the highest output, claimed at 260 lumens.  I measured 231, and a stepdown beginning around 1m15s.

The light didn’t really turn off during these runtimes.  The switch does indicate remaining power, and there’s a stepdown to very low output, however.

With the built in battery comes built-in charging as well.  This is by way of a USB-C port.  A charge cable is not included.  I have plenty of the right cables (USB to USB-C or USB-C to USB-C.  Connecting USB-C to USB-C only charges at 5V, however.  If you don’t have any USB-C cables, you should factor this into your price.  (Note: The Fenix website does say cables are now included as of 8/20/20.  But if you buy elsewhere you may or may not get one.)

The charge port cover is a secure press-in silicone cover, and the port is very well fit into the opening.

Charging is a very consistent 0.2A, and requires around 84 minutes to complete.

Modes and Currents

Mode Mode Claimed Output (lm) Claimed Runtime Measured Lumens Tailcap Amps
High 260 45m 231
Med 80 1h15m 82
Low 30 3h 30
Eco 5 18h
Red 4 5h30m

Pulse Width Modulation

There is non-visible (very fast) PWM on the lower three white modes.  The red does not use PWM.

Red: (no PWM).

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’s an indicating e-switch on one side of the E03R.  The switch has a metal cover and is very pleasantly clicky.  There’s just enough texture so you’ll know which side of the light it’s on without extra effort, and it’s flush with the body.

The switch has some battery indicator functions which have been covered above.

Here’s a UI table!

State Action Result
Off Click Battery Indicator
Off Hold (0.5s) On – White
Off Hold (1.2s) On – Red
Off Double Click Lockout (indicated by double flash of white)
Lockout Click Indicator for lockout (two white flashes)
Lockout Double Click Unlock to Low
On Hold Off
On Click Mode advance
(ELMH for white)
(Red > Red Flash for red)

The UI is quite simple, but the Hold for on (of either emitter) did take some getting used to.

LED and Beam

There are two emitters in the E03R.  The white is a Match CA18, and the red is an Everlight 2835.  I haven’t experienced the Match CA18 before.  Both are behind a lightly frosted TIR.

With the switch on top, the white is on the right hand side.  In the photo below, the switch is “up” and at left (facing you) is the white, with red being the more clear of the two.

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!

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


What I like

  • Good build quality – no seams
  • Dual output
  • Good use of indicating switch
  • Very nice switch overall (the cover, the action, the size, the placement – everything about this switch is right)

What I don’t like

  • Built in (probably not replaceable) battery
  • Could use lower output on red (even if the higher was removed).


  • This light was provided by for review. I was not paid to write this review.
  • This content originally appeared at  Please visit there for the best experience!
  • For flashlight related patches, stickers, and gear, head over to PhotonPhreaks, another site where I write!
  • Use my referral link if you’re willing to help support making more reviews like this one!

1 thought on “Fenix E03R Keychain Flashlight Review”

  1. Pingback: Fenix E-Lite Multipurpose Mini EDC Flashlight Review - ZeroAir Reviews

Leave a Reply

%d bloggers like this: