MX ULP remains one of the most interesting mechanical keyboard innovations I've used, yet it's baffling why the industry never ran with it.
Back in 2022, I reviewed a keyboard that I still think about more than most hardware that's passed through my hands since. The Corsair K100 Air Wireless was, at the time, one of the most expensive keyboards I'd ever tested, and I said as much in my verdict, but I also called it one of the best keyboards I'd used full stop, and I meant it. What made it special wasn't necessarily its RGB, the iCUE software, or even the versatile wireless connection on offer.
It was its clever Cherry MX Ultra Low Profile switches. Several years on from my first look, that same technology still hasn't gone mainstream, and dusting the K100 Air Wireless off again is a good reminder of exactly what's been left on the table.
It's worth saying upfront that "slim" gets used as a catch-all term far too often in this industry, lumping together products that are actually solving quite different problems. A low-profile keyboard and an ultra-low-profile one sound like a difference of degree, a few millimetres here or there. However, in practice, I think they're closer to two different categories of product that happen to share a marketing buzzword, and the K100 Air Wireless remains one of the best exhibitions of the technology to the point I'm surprised it's still so underappreciated.
The real kicker for the K100 Air Wireless was its inclusion of Cherry's MX Ultra Low Profile Switches. You might think I'm being facetious by saying that as low-profile mechanical keyboards aren't a new thing, but there is a vital difference between low profile and ultra low profile. Short low-profile switches, the kind you'll find in something like Corsair's own K60 RGB Pro Low Profile or Logitech's G915 X Lightspeed, are a meaningful step down from a full-height Cherry MX switch in size.
ULP switches work via a different design altogether to the usual mechanical switch mechanism that's just been downsized, using metal "wings" that pivot down onto the actuator rather than a plastic stem pushing straight onto a set of crosspoints. That mechanism let Cherry get the total switch height down to 3.5mm and total key travel to just 1.8mm, packed into a board only 17mm tall at its thickest point.
On paper, it doesn't sound like much, and to some it could be the recipe for a mushy keypress you'd hardly want to return to. This comes especially as the ULP switches were only available in tactile flavour, with either a bump or a click under finger, and 1.8mm of travel doesn't really leave much room.
However, it's the genius of these switches that it works beautifully. The tactile bump on Cherry's MX ULP Tactile switches is short and sharp rather than the rounder, more drawn-out feel of a full-height switch, but it's genuinely there, and genuinely satisfying. Even more surprising was the actuation force: at 65cN, these are about as heavy as one of my other favourites – the full-height MX Clear, which would normally leave your fingers fatigued over a long session. However, because the total travel of an MX ULP is so short, that fatigue never really materialises — your fingers simply don't have far enough to go for the extra weight to become a problem. It's a genuinely clever piece of engineering, and using it convinced me that ultra-low-profile was a feature to shout about in its own right.
سەرچاوەی فەرمی بە زمانی ئینگلیزی: https://www.ign.com/articles/cherry-mx-ulp-switches-desktop-keyboards
