McE2S resting between 2 stock Surefire
The McE2S is a professionally made guarded tailcap
for E series Surefire flashlights. Specifically designed
for LED head applications, it provides 2 levels of brightness
when used with the L4 Digital Lumamax or an E2e body
with the KL1 Luxeon LED head. After replacing the standard
clickie switch with this new lock-out tail cap (no,
it's not a clickie) you will have a low output level
available in addition to your regular high output level.
Although the tailcap simply uses resistors to provide
the lower level of output, high output is still regulated
by the internal electronics in the L4 or KL1 as normal.
There are four levels of resistance available: 15 ohm,
22 ohm, 30 ohm, and 60 ohm. The unit evaluated is a
22 ohm and it produces very good light with the L4 in
low mode. In fact it was very close in throw and overall
output to an Inova X5T by my measurements. If you are
more concerned with preserving night vision, or want
very low output, you may want to try the 30 or 60 ohm
models. I would recommend going with the 30 ohm for
E2e-KL1 applications since the 22 ohm tailcap caused
the regulator to just barely kick in and flicker with
L4 with McE2S installed (looks like it came with the
light, doesn't it?)
The tailcap itself is aluminum with a Hard Anodize
Type III finish to match the E series lights. It is
nearly impossible to make a perfect match for color,
so expect that it will be a little lighter or darker.
The top of the switch has a ring that extends just above
the level of the rubber switch boot so that the light
may be turned on and set on its tail for illuminating
a room. The lower section of the switch is checkered
for grip. Depressing the central rubber boot allows
for momentary operation, twisting the switch allows
for constant operation. Whether pressing the button
or twisting on, the first stage is low, the second is
the standard high output. If the switch is twisted so
that the light is on in low mode, depressing the button
will momentarily turn the light on high.
Around the top of the upper protective ring on the
switch are two holes for lanyard or accessory attachment.
One is threaded, the other is not. Also, on the body
of the switch there is a "witness mark" similar
to those found on regular Surefire tailcaps, except
this witness mark is also a threaded hole for accessory
Inside the switch housing is a unique mechanical arrangement
which allows for two levels of brightness from a standard
L4. Depressing partially permits contact through a special
ring which contains resistors. This essentially "starves"
the regulator circuit inside LED head and causes the
light to illuminate at a low level in "direct drive"
mode. Although this is an inefficient use of the batteries'
energy, the added utility of the lower level more than
makes up for it. Pressing harder causes a second contact
to engage and this allows the full current from the
batteries to go to the internal regulator circuit in
the flashlight and it comes on at full output.
Since the springs that allow for the operation of the
switch include the spring that retains pressure on the
batteries, compressing the switch does require some
effort. Add to this the fact that the protective ring
around the rubber switch boot forces your to push in
on the switch from a higher angle than is necessary
with the stock switch and you quickly wind up with a
sore thumb! Rather than holding the light in a tactical
grip with the thumb on the switch, it is much more comfortable
to use a "stogie" grip - similar to how you
may hold a cigar. Pressing with the thumb is then at
a much more comfortable angle.
The only other problem I had with the switch is that
its large diameter precludes my carrying my light in
my favorite belt sheath - a flap adorned Minimag holster.
If this is a real problem for anyone, a Streamlight
Scorpion belt sheath could be used instead, or you can
purchase just the dual stage "guts" for the
switch and install it in your own Surefire Z52 (lock
out type) or Z57 (clickie) switch.
By the way, here's a bonus tip: if you would
like to diffuse the beam of the L4 or reduce its output
even further, the cap off of a Deer Park 0.5 liter bottle
of water fits perfectly over the bezel of the L4 (and
the rest of the E series bezels as well, including the
KL1). I find that the low output of the McE2S works
great with the bottle cap diffuser if I need an even
dimmer light. Using the new tailcap in conjunction with
the diffuser cap turns it into a great area lantern
with 360 deg spread of diffuse light since the new switch
allows the light to stand on end. The cap protects the
lens and if you lose it, you just have to buy another
$1 bottle of water!
More information about the history of this modification
from its maker can be found here: http://dmcleish.com/CPF/McE2S/index.html
The tailcap will be available for purchase here: http://www.anlighten.com/shop/default.php
If you buy just the kit and want to install it yourself,
check here: http://www.obaq.tv/cpf/?page=McE2S
Conclusions: It may take a little getting used
to, but the McE2S is a GREAT upgrade for the L4 to increase
its utility. Also works on the KL1. It is not intended
for incandescent E series heads.