Isolate It!Sorbothane Acoustic & Vibration Damping Film 40 Duro with 3M Adhesive (0.10 x 6 x 12in) - 1 Sheet

This works pretty great, and if you are already spending god knows what on your keyboard, why not go the extra distance to add some weight and make you case feel like it was carved from Thor's Hammer. It is a little tricky to work with because even if you leave the transfer paper on the topside is quite sticky, it gets gross very easily, so wait to take the plastic off if you can. It can be cleaned efficiently with a wet sponge.Cutting is easy if you keep the clear plastic on, poking holds for the standoffs is much trickier. I tried to use a drill, NOPE. I think and awl might be your best bet, or some kind of mega hole puncher. I mangled on of mine, and had to cut another little piece to fill it the hole, for my ocd.This size is perfect for the Tofu 65 case. Cut is to 12 X 3.75 inches. Use the extra to cut a piece that will fill in the cutout in the bottom of the case. Your pcb will fit snug up against the material which is ideal.NOTE: If you need to take your pcb out of the case, this stuff is coming with it, it will stick.Final Verdict: This is some great money invested in your high end build, it will make the case feel and sound as extremely dense and reduce a large amount of ping resonance without having to use o rings.

I used this for a mechanical keyboard mod, I added it as a layer between the case and the plate/pcb. Made this aluminum keyboard case feel even more solid and reduced typing noise by at least as much as advertised. Not hard to cut, make sure you take your time and use a sharp blade.

Very good poron foam sheet, but very costly (2)

Sticks good. A little firmer/solid than I expected.