After my Surefire G2 review, I talked to Gene Malkoff about sending some LED replacements.  He agreed and sent the M61L, which is suited for the nitrolon body of the Surefire.  He also threw in the package the big brother of the M61L, the M61, which is similar aside from the “L” – where “L” stands for “low output.”  This is the review of the M61!

I’ve reviewed similar items like this as one review before, but this will be separate posts.  I think that’s a better separation of material, and should end up being a bit clearer in the long term.  Let me know what you think of that!

Official Specs and Features

Here’s a link to the official product page.


In the sense of this dropin, there’s only this one.  But more generally speaking, this dropin body is available in many configurations.  There’s the M61, which isn’t low output, but single mode.  There’s the other one I have, the M61L, which is a single mode low output.

But there are a bunch:

M61 Mod to fit Surefire and Malkoff
M61L (Low Output) to fit Surefire
M61LL (lowest output) to fit Surefire
M61N (neutral tint) to fit Surefire and Malkoff
M61NL (neutral tint, low output) to fit Surefire and Malkoff
M61NLL (neutral tint, lowest output) to fit Surefire and Malkoff
M61W (warm tint) to fit Surefire
M61WL (warml tint, low output) to fit Surefire
M61WLL (warm tint, lowest output) to fit Surefire
M361-LMH Low-Med-High to Fit SureFire
M361N-LMH Neutral Low-Med-High to Fit SureFire

And there are even others, not really for the G2, but still using basically the same brass parts.


This specific dropin is $43.99, on sale from $55.00.

Short Review

This is a very nice upgrade to the metal body Surefire P60 (etc) incandescent dropins.  It’s extremely well built, and dead simple.

Long Review

The Big Table

Malkoff M61
Emitter: Cree XP-G2
Cell: CR123x2
Switch Type: Mechanical
On-Board Charging? No
Claimed Lumens (lm) 450
Measured Lumens (at 30s) 611 (135.8% of claim)*
Claimed Throw (m) 107
Candela (Calculated) in cd (at 30s) 275lux @ 4.533m = 5651cd
Throw (Calculated) (m) 150.3 (140.5% of claim)*

The other setup:

Malkoff M61
Cell: 18350
Claimed Lumens (lm) 450
Measured Lumens (at 30s) 393 (87.3% of claim)*
Claimed Throw (m) 107
Candela (Calculated) in cd (at 30s) 393lux @ 294m = 5785cd
Throw (Calculated) (m) 152.1 (142.1% of claim)*
All my Malkoff reviews!
  • Standard 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

  • Malkoff M61 dropin

Package and Manual

This dropin ships in a plastic blister pack, which is easily opened without cutting.

There is no manual.  It’s plug and play.

Build Quality and Disassembly

This is a very nice dropin.  It’s extremely solid.  The electronics are potted, so there’s nothing to move or manipulate or …. anything.  It’s just a solid chunk of dropin.

Same spring as the M61L.  Same comment:

Though I don’t know what the reasons are, I expect this narrow-to-broad spring is used purposefully.  I would probably prefer a bit of a stiffer spring, especially if intended as a weapon light.

The specific dropin name is scratched into the brass body.  This is effective, and reasonable since the guts are potted and thus essentially permanent.  A sticker with the dropin name be nice.  Particularly if that sticker had dropin specifics like voltage range.

Size and Comps

Here are the dimensions, as measured by me:

Largest diameter: 26.16mm
Narrowest diameter: 18.46mm
Length: 29.0mm
Length including uncompressed spring: 34.68mm

Exactly the same as the M61L.

Power and Runtime

I threw this dropin in a random P60 host I had on hand, which happened to be a Solarforce L2M (seen above).  The dropin voltage range is 3.4V to 9V.

Since I don’t test with primary cells, I tested with a 18350 Li-ion cell.  That voltage is 4.2V.  As a result, my max output will likely be a little lower than with a two-cell setup.

The pic below is the liion cell I tested the dropin with.

As you can see, I measure around 393 lumens at 30s on a 4.2V Li-ion.  The spec is 450 lumens, but that’s on 6V 2-up cells.  Unlike the M61L, the output drops almost immediately, and seems to be direct drive for the entire runtime.  I had a glitch in the test where the light dropped down and turned off, but it restarted and continued.  I’m not sure exactly what happened in this case.

I’ll add that to get this dropin to work in the Solarforce host, I needed to add two magnets, for a total of around 4mm thickness, on the negative terminal.  A longer spring on the dropin would likely fix this.

There is no LVP.

Pulse Width Modulation

There is 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

No UI table is necessary. The mechanism for this dropin is either on or off. If a circuit is made between the spring, body, and a cell, the dropin will be on.

In the case of the Solarforce L2M, the switch is a mechanical forward clicky.  But the dropin doesn’t care what type mechanical switch is used.

Modes and Currents

Mode Mode Claimed Output (lm) Claimed Runtime Measured Lumens Tailcap Amps
6V 450 1.25h 611 0.65
4.2V 450 393 0.76

LED and Beam

The emitter used in many of these dropins is a Cree XP-G2 Cool White (6200K).  Some of the others are specifically labeled as being other temperatures, though.  The reflector is lightly orange peel, and not terribly deep.

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

6V (CR123x2):

4.2V (16650 Liion):

Tint vs BLF-348 (Killzone 219b version)

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


What I like

  • Robust build quality
  • Low output considers nitrolon body of Surefire G2
  • PLENTY of options in the line, to get whatever is wanted

What I don’t like

  • Prefer a stiffer spring
  • Would like LVP


  • This light was provided by Malkoff for review. I was not paid to write this review.
  • This content originally appeared at  Please visit there for the best experience!
  • Whether or not I have a coupon for this light, I do have a bunch of coupons!!  Have a look at my spreadsheet for those coupons. It’s possible to subscribe and get notifications when the sheet is edited!!

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