Small keyboard fans, this is a must-see.
On September 22, 2025, Jezail Funder Japan began handling the new LCK-40S & Ergo transparent black keycap set.
The keycap set is designed for 40% layout keyboards with low-profile mechanical key switches, mainly for home-built keyboards and NiuNiu @40 /Daisy layout keyboards.
This article reviews the newly released LCK-40S & Ergo keycap kit.

Representative of GreenEchoes Studio
He launched his own media as a site operator and web writer, and now plans and manages multiple corporate media. He often types heavily in his work, and in his search for greater efficiency, he became addicted to the keyboard swamp and established “GreenKeys”.
Jezail Funder LCK-40S & Ergo Keycap Set Overview


- Coloring: black or clear
- Material: PC (Polycarbonate)
- Stem Shape: Cherry MX Cross Axis
- Profile: LCK profile (profile with depressed center)
- Difference in slope by row: None
- Price: 4,620 yen (tax included)
Jezail Funder LCK-40S & Ergo Keycap Set Review
Let’s take a look at the LCK keycap.
It comes in the usual paper packaging familiar to Jezail Funder.


The package design is simple but well thought out.
I would also like to learn from the fact that the same paper sleeve can be used even if the tray has three tiers. (Seller’s perspective)

Because the kit is designed for 40% keyboards, it has two trays and a small number of keys.

There are no function keys, as it is designed for a 40% keyboard.
It consists of two alpha keys, one centered on the 1u size and the other on a special size mod key diversified by 40% size.

It is noteworthy that there are also a number of convex ski caps.

Personally, I think it would have been nice to have one more convex keycap around 1.25u/1.5u each for use on left/right target karasta keyboards such as Corne.

The keycap material is polycarbonate and the printing is believed to be UV printed.

The printing is quite solid and does not seem to be likely to come off even if scratched.

There is no misalignment of the print position, and the quality is good.

Unusually for a keycap, the Alpha key legend is a small legend.

The italicized, thin line font looks beautiful and stylish.

Compare the Convex keycap with a regular keycap.

Convex is on the left and regular keycap is on the right.
It is a slight difference, but it is still very easy to type when there is a convex on the thumb key.



The molding of the cross stem is very solid and does not seem to be crushed in terms of strength.

There are molding marks, but they are not noticeable.
It is carefully finished without burrs.

Now let’s actually put it on the keyboard.
We chose NiuNiu’s @40 keyboard.
The layout is as a QAZ with 1u open in the center.

The color is black transparent, but the color of the key switch is faintly visible, which is also stylish.

Homing is dot-shaped.
It is modest, but functions perfectly well as a homing key.

From the side, you can see that it is a flat profile with no difference in slope from row to row.

If you normally use a laptop computer, you are most likely to use stroking, so the flat type will be easier to type on.

The spherical shape of the keys, which are recessed toward the center of the keys, naturally guides the fingers to the center of the keys, giving them a “sucking” sensation.

The circular indentation reflects light, making it a beautiful keycap, including the reflection.

Convex keys in the thumb area are also easy to press.

Basically, as far as MOD key icons are concerned, they follow the Mac.
There is no Win key, so you may need to consider replacing it accordingly.


As a side note, please note that the font is different from the set keycap of the Gravity45LP kit.






Summary|Recommended for people with small keyboards

This is my review of the Jezail Funder LCK 40s & Ergo keycap kit.
Smaller low-profile mechanical keyboards are all the rage these days, but there are few keycap options.
As for keycaps for low-profile mechanical keyboards on the market, unfortunately, most of them are for full-size keyboards, and there are few options for so-called “minor size” keycaps, which are 40% or smaller.
With that said, the LCK 40s & Ergo kit is an “itchy” kit.
I would highly recommend this keycap set to small keyboard enthusiasts.
Please consider purchasing one!
Tap the tag you are interested in
Article List Basekeys. Cannonkeys. Cerakey Chosfox Drop ELECOM Epomaker FKcaps Grovemade HHKB HHKB Studio Keycaps Hippokeys home-built keyboard Jezail Funder JezailFunder Kailh. KBDfans KeebPlus key (mahjong) Keyboardio Keychron key switch kirkette Logitech Mojo68 MONSGEEK NEWS Niuniu NuPhy OMNITYPE ONEPLUS PMD restrained style see the fluffy ones Sonnet split keyboard STOCK tadpole TEX trackball mouse WOBKEY. work louder YMDK ZENAIM