HONKID Keyboard Foam, Sound Dampening Foam for Mechanical Keyboard Bottom, Made of LE-20 Poron, Black (H 2mm)

Honestly for the price I feel like you should get more than one keyboards worth. Not like 20sq ft or anything but dang. It does help get some deeper thocks though! Easy to cut to fit, sounds great, and stable.

Excellent foam. Works great. The only complaint I could possibly have is that they don't pre-cut it into perfect sizes for keyboards. You'd think they'd do that to save on wasted foam and just provide one size fits all for the various form factors but no biggie, just cut it to size and you're good to go.

There is probably a bunch of stuff you could put in your keyboard to dampen sound lying around your house, but you were curious, and the internet led you here, to poron foam. It's true, this stuff is good. I had a fun little project upgrade a budget Redragon board with Outemu reds (the most pingy, hollow board I've ever heard), and this poron foam combined with aditional sound dampening foam between the PCB and the plate and a tape mod turned this awful-sounding board into an absolute DELIGHT to type on. Again, poron foam is just part of the equation, but this stuff worked, and I've got a bit left over since the board was TKL and there's enough foam for a full size board. Would buy again!

Just a roll of Poron to cut for your keyboard. I used one later for the bottom of my GMMK Pro. Its nothing special, but it does exactly what you want it to for case ping and sound dampening. Appears to be legit Poron and not some fake foam. Can be a pain to cut, so make sure you have a good cutting utility.

There's only so much that interior insulation can dampen sound, and this one does all that is possible to do. Which is a noticeable improvement, but still not conventionally "quiet". And after doing DasKeyboard "technical support"'s job for them (they should pay me) by ripping my DasKeyboard apart to meaure the interior myself because DasKeyboard "technical support" inexplicably refuses to have a DasKeyboard office intern access the DasKeyboard document archive and read the DasKeyboard interior dimensions off the DasKeyboard mechanical drawing, I can report that the minimum clearance dictating the maximum foam thickness inside a DasKeyboard is 2 mm (5/64").