YLP Gekko 1.0 Headlamp Review

Only recently released is the YLP Gekko 1.0 headlamp, an 18650 flashlight with a nice feature set.  But more importantly, it has a great emitter choice!  Read on.

YLP Gekko 1.0 Headlamp Official Specs and Features

Here’s a link to the YLP Gekko 1.0 headlamp product page.


I believe there’s just one version.


These are selling for $47 at this time, and available at the official YLP website.

Short Review of the YLP Gekko 1.0 Headlamp

Great headlamp!  Extensive user interface options, if you want them, but they stay out of your way if you don’t. Great emitter choice, and the default user interface is probably “enough.”

Long Review

The Big Table

YLP Gekko 1.0 Headlamp
Emitter: Samsung LH351D (Neutral White 4200К, Min 90CRI)
Price in USD at publication time: $47.00
Cell: 1×18650
Maximum Runtime Graph High Runtime Graph
LVP? Yes
Switch Type: E-Switch
Quiescent Current (mA):
On-Board Charging? No
Claimed Lumens (lm) 900
Measured Lumens (at 30s) 715 (79.4% of claim)*
Candela per Lumen 3.1
Claimed Throw (m) 85
Candela (Calculated) in cd (at 30s) 217lux @ 3.226m = 2258cd
Throw (Calculated) (m) 95.0 (111.8% of claim)*
All my YLP 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

  • YLP Gekko 1.0 Headlamp
  • Spare tailcap, with magnet
  • Spare o-rings (2)
  • Headband
  • Manual

Package and Manual


There’s a bunch more manual, but let’s cover that below.  Here’s a link, though:

Build Quality and Disassembly

feature photo

The YLP Gekko 1.0 headlamp has a striking appearance.  Notably, it’s not black!  So many flashlights are black, but this one has a what I think is called “natural” anodization.

Yes, it looks quite like a Zebralight in finish.

Here’s a top-down view.

top down views

top down views

top down views

top down views

The head has some nice deep cooling fins, which as you’ll see later, are quite needful.

cooling fins

These tailcaps (both of them, more on that later), have minimal, but very aggressive knurling.

tailcap knurling

Threads on the tailcap end are short, anodized and fairly smooth.

tailcap spring and threads

The YLP Gekko 1.0 headlamp ships with two entirely separate tailcaps.  One doesn’t have  a magnet (above) and one has an exposed magnet (below).

tailcap magnet

The two tailcaps fit interchangeably.

two tailcaps

The magnet tailcap (seen at right below), is much taller than the non-magnet tailcap.

cell installed

This adds length to the headlamp.

two tailcaps size

Both tailcaps and also the head end of the light have springs.  These springs are considerably stiff, too.  Good springs.

inside cell tube

Here’s what appears to be a completely random photo, but I intended to show that the bezel is a screw-in type bezel.  It has five points inside.

random photo

Size and Comps

Length: 104mm
Height: 24mm
Diameter: 21mm
Weight (light only, no cell): 48g

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).

ylp gekko 1.0 headlamp in hand

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

As a headlamp, the main means of carry here will be the included headband.


It’s a nice headband.  These loops are stretchy silicone, and make the light easy to get in and out.


The over-the-head strap is removable, and just that little tap atop the connector remains.


You’ll really have to disassemble that whole strap to remove it, though.

All of the bands are covered with the double band of grippy silicone, too.


The YLP Gekko 1.0 headlamp fits into the bands nicely.  The bands sit in groves on the light body.


It’s possible and easy to rotate the light around within the connector.



There is no pocket clip included, so there’s no pocket clip to get in the way of the headband.

Also included as mentioned above, is this magnet tailcap.


It’s strong enough to hold the light horizontally.

magnet retention

There is no pocket clip, no pouch, and no lanyard.

Power and Runtime

The YLP Gekko 1.0 headlamp is powered by a single 18650 cell.  The cell goes into the light in the normal orientation, which is positive terminal toward the head.

cell installed

Here are a couple of runtimes.  The light does have LVP, and I see the light turn off at around 2.83V.  Also note that the switch indicates red and green.  Green means power is ok.  Red means the cell is low.  And unusually, the switch can also indicate in red and green at the same time, which means “power is somewhere in the middle” (roughly.)

Technically this does mean specific things:

Green: >3.8V
Green+Red: >3.5V
Red: <3.5V

YLP calls the highest output “Maximum” not “Turbo.”  Also note that the output is thermally controlled.  As internal temperature increases, the output may be modulated to reduce the heat.

runtime graph maximum

Output on High is very stable for the duration.  Very respectable.  “High” of around 235 lumens is arguably low, for “high” though.  But such is the nature of high CRI, warm emitters.  Can’t really fault YLP for this.

runtime graph high

The YLP Gekko 1.0 headlamp does not have any charging features.

Modes and Currents

Mode Mode Claimed Output (lm) Claimed Runtime Measured Lumens Tailcap Amps
Maximum 900 1.5h 715 2.64
High 300 4.5h 235 0.65
Medium 100 14h 0.21
Low 33 40h 0.07
Moonlight 1 5d 0.01

Pulse Width Modulation

What you see below isn’t really PWM, it’s a sawtooth of some sort.  But not noticeable, either way.

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 a single indicating e-switch on the Gekko 1.0.  It’s gray, and can indicate red and green.  It’s quite clicky, too.

indicating switch

switch profile


Here’s a UI table fo the Basic UI!

State Action Result
Off Click On (Mode memory)
On Hold “Sine wave” mode changes (lowest to highest back to lowest, repeating)
On Click Off
Off Double click Maximum*
Off Hold Minimum*
On Double Click Maximum
Off Click 14x Advanced UI 1 (ramping, while maintaining Min/Max access)
Advanced UI 1 Click 5x + Hold Advanced UI 2 (also ramping, but more, including some strobe options, battery check, tactical mode (completely momentary operation))
Advanced UI 2 Click 5x + Hold Advanced UI 3 (similar to the Basic UI, but with some memory change options, some switch indicator change options and other things)
Any Advanced UI Click 12x Returns to Basic UI
  • Activations like this are not stored in memory

Advanced user interface details can be seen below.

gekko engineering manual

Advanced UI-1 (smooth adjustment)

Brightness is gradually adjusted by holding the button, the selected brightness level is stored in memory.

Holding the button changes the brightness upward, re-holding after a short pause – downward. You can also use the “click + hold” command to move down.

The flashlight is in the adjustment state for one second after the button is released. In this state a short click allows to change the brightness to a small value for more precise adjustment.

If the button is held for more than 1.5 seconds when the maximum level is reached, the flashlight activates non-latсhing Maximum mode; when the button is released, the flashlight will return to the additional mode. Also, it is possible to activate the Maximum mode with two short clicks (from any state), and turn the flashlight ON in the minimum mode with press-and-hold the button. To get to advanced UI-2 use command “5 clicks and hold”.

Advanced UI-2 (extended smooth adjustment)

The flashlight keeps the smooth adjustment mode with extending the additional commands list:
2 clicks – Maximum mode.
2 clicks + hold – turn on at Maximum and scroll the brightness from top to bottom.
3 clicks – strobe. The brightness of the strobe is controlled by holding the button.

3 clicks + hold – beacon (main LED). The brightness of the beacon depends on the
mode used previously.
4 clicks – check battery status.
4 clicks + hold – tactical mode, the flashlight will light only while holding the button. To exit
the tactical mode, unscrew and tighten the tailcap.
5 clicks – turn on / off the backlight of the button (for the OFF state).
6 clicks – On/Off beacon of the button.

To get to advanced UI-3 use command “5 clicks and hold”.

Advanced UI-3 (extended discrete adjustment)

This interface uses five discrete modes, same as in basic operation mode, with extending
the additional commands list and a possibility to control the button backlighting and the memory of modes.
2 clicks – Maximum mode.
3 clicks – strobe. The brightness of the strobe is controlled by holding the button.
4 clicks – check battery status.
4 clicks + hold – turn on / off the memory of modes.
When the memory is ON, the flashlight blinks with GREEN indicator LED – the standard
memory of modes will work.
When the memory is OFF, the flashlight blinks with RED indicator LED – the last used mode
will be set as the starting one for all the following power-ups.
5 clicks – turn on / off the backlight of the button (for the OFF state).
To get to advanced UI-1 use command “5 clicks and hold”.

Engineering Mode

But wait, there’s more!

The YLP Gekko 1.0 Headlamp has an advance user interface setup option that will allow the user to change things like thermal settings, how the strobe works.

I’m interested in your input about this – have you used the engineering mode on your YLP flashlight?  The Unicorn 1.0 had the same setup, and you all have a Unicorn, right?  Let me know in the comments!

LED and Beam

YLP opted for a Samsung LH351d in the Gekko 1.0 headlamp.  I consider that a great choice.  And what’s better is that this is a high CRI, 4200K version of that emitter.

emitter and tir

The emitter is behind this dimpled TIR, and has a nice even beam because of it.

emitter and tir

emitter profile view on


I am pleased that YLP went with this warmer emitter, at the cost of probably a reasonable amount of lumens.

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

Tint vs BLF-348 (KillzoneFlashlights.com 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 KillzoneFlashlights.com 219b BLF-348 because it’s inexpensive and has the best tint!


What I like

  • Good emitter
  • 4200K is a great choice!
  • High CRI is a nice bonus
  • Extremely advanced user interface (there if you want it!)
  • Magnet tailcap (or not!)
  • Indicating switch
  • Good low voltage protection

What I don’t like

  • Two tailcaps – probably run the cost down by a few dollars and drop one of the tailcaps.  Or offer me the option.
  • Length – 104mm is quite long
  • No pocket clip


  • This light was provided by YLP for review. I was not paid to write this review.
  • This content originally appeared at zeroair.org.  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 amazon.com referral link if you’re willing to help support making more reviews like this one!
Liked it? Take a second to support zeroair on Patreon!

1 thought on “YLP Gekko 1.0 Headlamp Review”

  1. Pingback: Flashlight News: Phreaky Briefing Issue 39 – PhotonPhreaks

Leave a Reply

%d bloggers like this: