Switch: Kailh Red BOX V2

Kailh was originally planning to have media briefings—both in person and online—for the launch of the BOX Hush and newer BOX V2 switches, but then COVID decided it wasn't done just yet. Instead, I was offered one of the world's first BOX V2 switch samples to talk about if interested, and the original plan was to do a 65% keyboard build before Kailh decided to ship me a full set of 110 switches for each of the three new BOX V2 switches. These came in branded plastic containers, and I decided to begin with the Kailh Red BOX V2, which may also be referred to as the Kailh BOX Red V2 in some places. No matter the naming scheme, this is version 2 of the original BOX Red, which itself is a big update to the Kailh Red mechanical switch originally made after Cherry's MX patent expired. The Kailh Red is a clone of the Cherry MX Red in nearly all ways imaginable, but the BOX Red is significantly different. With the BOX V2, we see an evolution of the design rather than another revolution, however.


Having covered the original Kailh BOX Red switch before, I show the two side-by-side for an easier comparison. The obvious external change is that the new Red Box V2 switch uses a black instead of white bottom housing, and a 5-pin instead of 3-pin design. LED support is also slightly different, no longer allowing for a surface-mounted LED since SMD LEDs have become the norm for backlit keyboards. Otherwise, the two occupy the same footprint, which has any kit or keycap set that worked with the original work with the new BOX V2.


Disassembling the Kailh Red BOX V2, we see the decoupled actuation mechanism of the successful BOX switch concept as a whole. Two sets of interlocking tabs keep the switch together. The Kailh Red BOX V2 is a linear switch adopting the Cherry MX cross-point stem design with a clear top, red stem, metal spring, and base housing that also houses the metal leaf contact. A typical mechanical switch has the stem travel down and touch one side of the metal leaf, which is in turn pushed towards the other side. This metal contact then triggers the actuation of the keystroke on the PCB, and off it goes to your computer to be reflected as an action. With the BOX series, Kailh added an intermediate plastic nib it calls the Active Block that is lubed well, too. The plastic of the stem thus only touches this green plastic nib, which in turn pushes the moving metal plate onto the stationary metal plate for actuation. Thus, the metal contacts are isolated and covered, which is how these switches got the IP56 rating. The linear BOX switches are the simplest to understand, which is why I started with the Red switch.


The various internal components have also been updated with the BOX V2, including the housing. The top is a different, darker color, and Kailh says the top and bottom both have enhanced positioning columns to minimize stem wobble as it moves up and down. It's subtle, but visually discernible with the two next to each other. The spring is also longer and gold-plated, with the longer stem arguably allowing for more linear feedback in addition to a quicker rebound. The stems seem identical, but the contact surface is more heavily contoured rather than a triangle coming off the primary stem. There is also an extension on the other side, which clicky switches employing a click-bar mechanism usually have—it does nothing at all in this case. Perhaps it is a case of Kailh simplifying its molds to have a single base design? We shall find out soon enough, I suppose. The base is in a different color, too. Overall, I see more regular molded parts with the Red BOX V2 than BOX V1, which has irregular lines, especially on the stem.


Using the Kailh Red BOX V2 switches with the Akko MOD 003 kit is quite simple, especially as 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. Just ensure the metal pins are straight before aligning them with the openings of the switch socket and press down vertically until you hit a solid wall. Go in at an angle or with slightly off-centered or angled pins and you might encounter resistance sooner or even hear the scrunching of the pins being bent or crumpled further. The BOX switches also provide further support courtesy the columns around the cross-point stem, which are meant to add further dust and spill resistance, but help you hold on to individual BOX switches. Once done, the switches don't really match the dark green color of the kit, but you are not going to see them once the keycaps are installed anyway.


Speaking of which, above is the default key layout for the Akko MOD 003 with the keycaps installed accordingly. Having recently covered the Akko 3098 helped, especially in identifying which four keys go above the numpad. I had to go through all three layers of the keycap set to install all 98 keycaps, and have to say that this color scheme looks even better in person than it does in these photos. The secondary colors break up the monotony, and I was otherwise pleasantly surprised by how well the base color matched the case. A look from the side also confirms the Cherry profile, which works fine with the switches and north-facing LEDs. There are the usual six rows with less contouring, a combination which makes for a keyboard that is not too tall and still easily usable without a dedicated wrist rest.


This is the force-travel curve for the Kailh Red BOX V2 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 a rated actuation distance of 1.8 +/-0.4 mm as opposed to the average switch at 2.0 mm. This is the same as the BOX V1, but the rated actuation force is lower, at 40 +/-10 gf, another departure from the usual Red linear switch actuating at 45 gf. Peak force when bottoming-out is further decreased from 60 gf on the previous version to just 50 gf here, making the Red BOX V2 a light and fast switch. It only takes ~15 gf for the switches to rebound. On this keyboard, these were extremely consistent across the entire range. 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 from the usual. Since you will very likely bottom out, it's good to know that the total time between keystrokes is also shorter owing to the appreciably shorter travel distance. These are really good linear switches, and the tighter tolerances from V1 to V2 add positively to the user experience.


Here is what this specific combination sounds like when typing at ~105 WPM, and keep in mind that the sound profile is heavily influenced by everything. Even the aluminium case matters, with cases out of plastic, acrylic, or wood changing things drastically, too. 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 combination. I can tell you right away that these switches sound plenty fine in person, but it's really the gasket mount kit doing it here. Based on a quick comparison, the switches sound quieter than on standard plastic or plate-mount kits, and end up sounding deeper than the individual switches by themselves. The gaskets and foam pieces in the kit add positively to the experience, as does the PBT keycap set, but the unlubed, relatively inferior stabilizers unfortunately take away from what could have been a truly high-end experience. There is certainly scope for improvement thus, and I recommend re-lubing the stabilizers if you are so inclined. For context, you can find sound clips from other keyboards here, including those with linear switches.