Switch: Kailh Red Bean Pudding

We now get to the main event, and it is a five-parter too, so grab some snacks and settle in. Kailh might be my favorite keyboard switch manufacturer already, with the excellent BOX switches providing many variations to appeal to different tastes. The recently announced BOX Hush is also the quietest mechanical keyboard switch I have used to date, and it happened to launch after the focus of this article came out. Referred to as the new Master Series, it includes four recent switches with different inspirations and colorways, but a similar composition and design language. The first of these we are looking at is the Red Bean Pudding, after the dessert of the same name. If you purchase these switches directly from Kailh, they will ship in a plastic ziplock bag as seen above. I want Kailh go with something more substantial and protective, if only to prevent the metal pins from deforming/bending or even scratching the body of other switches. I asked for 120 of each switch type to have enough for the GK108 and a few spares for disassembly and further testing.


If it were up to me, I would have had a darker shade for the base to reflect the red beans themselves. But there's no denying that this is a unique looking switch, one that makes a strong first impression with the color scheme itself. It looks similar to the BOX Red, although a 5-pin switch with two plastic supports to minimize switch wobble further on top of the usual 3-pin structure (central pillar + two metal pins). This is a linear switch, and I chose to begin with it to go linear-tactile-clicky in this series of added complexity. Kailh is using only POM for the top cover and bottom base, which get the light reddish brown treatment. The stem guide is a darker red, probably the same as on the BOX Red. We see from the sides that the top cover is translucent to allow for diffused light, and one of the sides has a large clear plastic insert to aid backlighting as a light guide post.


Disassembling the Kailh Red Bean Pudding switch confirms this is also a BOX switch in design, as well as having a separate plastic insert. Note the molds used for the top cover, which allow for slider rails the stem travels up and down on smoothly without much wobble. The plastic insert is clear and trapezoidal in shape, which supposedly allows through over 90% of the light from an LED underneath the switch. I would have rather seen a more diffusing insert; while this current implementation can be brighter, it is harsher as well. The stem guide isn't lubed, although perceptive readers may notice some lube towards the bottom that comes from where it meets the active block element of the BOX switch actuation mechanism in the base. The columns around the cross-point stem make for added dust and spill resistance, and the body is no different from other such linear switches with a single bump to push something inward, and that something is the aforementioned active block.

However, the spring is different from the norm as it is shorter than the usual 14.5 mm at just 12.8 mm. Kailh used a stiffer, shorter spring in a move contrary to a few others going with longer, less stiff springs recently. The obvious benefit of a shorter spring is further stability in switch travel, although it does mean less leeway in the uniformity of feedback resistance. The base is where we see the BOX, with a cover over the metal stems to increase dust and spill resistant, which is enough to merit an IP56 rating. With the BOX series, Kailh added an intermediate plastic nib, the active block that is lubed well, too. The stem thus only touches this green plastic nib, which in turn pushes the moving metal plate onto the stationary metal plate for actuation.


Using the Kailh BOX Red switches with the Skyloong GK108 is quite simple, especially considering the socket is compatible with 5-pin switches out of the box; thus, you do not need to clip off two plastic pins per switch. All you have to do is ensure the metal pins are straight before orientating the pins based on the openings in the switch socket and pressing down vertically until you hit a solid wall. If you go at an angle or the pins are slightly off-centered, or angled, you might encounter resistance sooner or even hear the scrunching of the pins being bent or crumpled further. Once done, the switches look imposing up against the white plate and black case. I also appreciated that the plate has a smoother, more glossy surface treatment now. This means it is less likely to scratch when using switch remover tools to extract switches.


This is the force-travel curve for the Kailh Red Bean Pudding switches courtesy Kailh. These are medium-force linear switches with a total travel of 3.6 +/-0.3 mm instead of the usual 4.0 mm and rated actuation distance of 1.8 +/-0.4 mm, as opposed to the average switch at 2.0 mm. Rated actuation force is 45 +/-10 gf, which is slightly better than the average +/-15 gf error bar, but still not optimal for what is supposed to be a high-end switch. Peak force is closer to 55 gf, which you will hit when bottoming out and letting go in practice. As far as the rated specifications go, this switch is quite similar to the BOX Red in terms of the shorter overall travel, but the peak force is even lower to where the gap between actuation force and bottoming out is negligible. I dare say everyone will end up bottoming out here, which means these will not be the quietest switches in the world no matter which kit/keycaps you use them with. A random set of twenty switches tested well within rated specifications, with measured actuation at ~1.9 mm. Key travel is quite smooth with only plastic on lubed plastic contact, and you would be hard-pressed to make out a difference in actuation even with the slightly lower travel distance. If you don't mind bottoming out, these are really good linear switches, just not necessarily the best implementation of the BOX design itself.


Seen above is what is in my opinion the default fit with the Skyloong silicone keycaps for this configuration. In the absence of four R1 keycaps for the extra four keys on the GK108, I made do with some random extras. It does look quite the part. A look from the side shows the GK2 profile, which is quite high even on this high-profile case. It's also more aggressively contoured on the top and has softer, more curved sides make it quite similar to the SA profile.


If you thought the missing four keycaps were the snafu, that is unfortunately nothing compared to the real issue. Remember those light guide posts in the switches? They jut out horizontally past the angled body of the switches, and the plastic base of these silicone keycaps juts out horizontally, too. These just happen to be out-of-the-norm designs neither expected the other to have, meaning the two clash against each other, which affects switch travel. In some cases, this meant that force on the keycap pushed it down, but it not wanting to come back up easily. This is a situation you should certainly want to be aware of. I can confirm that the keycaps work fine with most switches, and these switches work fine with typical keycaps, too.


It's a good thing then that I had a spare set of keycaps I had not used before. This is where Akko enters the picture courtesy the World Tour Tokyo keycap set I had briefly shown in the review of a keyboard. Seen above is this set installed now, which also includes spare R1 keycaps for all 108 keys. This set uses the more common OEM profile, and I used it with the other four switches, too.



Here is what this specific combination sounds like, and keep in mind that the sound profile is heavily influenced by everything. Even the plastic case matters, with cases out of acrylic, wood, or aluminium changing things drastically as well. The presence or absence of sound-dampening foam is also quite the factor, which is why it's best to compare switches with the same case, plate, and keycap set combination. I can tell you right away that these switches sound nice, but not that different from others, such as Cherry MX Red or clones. Light reverberation off the relatively empty case does occur, and there is some pinging off the steel plate. We then get to the keycaps, and with all other variables being the same, the inadvertent issue allows for a comparison of how the silicone keycaps differ from the PBT keycaps,. Typing on the GK2 silicone keycaps takes practice, especially with the aggressive profile, but it really pays off, with a deeper, more satisfying listening experience, especially on the larger modifiers. Unfortunately, this positive experience is marred with sticky switches and obstacles in the travel path, but I am still a fan of this set for someone who prioritizes a deeper, thockier sound signature. For context, you can find sound clips from other keyboards here, including those with linear switches.