This is a new listing following up on the previous individual Corona 3 Full Kit, feet, and Spool Nut listings. You can find those options here:

Full Kit: https://www.ebay.com/itm/174799840230

Typewriter Feet: https://www.ebay.com/itm/174709052038

Spool Nuts (Amazing Working Rubber Design): https://www.ebay.com/itm/174715233337

THIS listing is for just  a set of four replacement "Inside Case Feet", or "Case Rubber", or "Case Pads", which are a very important part of the case design to protect the gorgeous paint on the folded Corona 3 typewriter when the case closes, and you carry it around. 

Basically, EVERY piece of rubber on these ~100 year old machines needs to be replaced, so I suggest you don't buy just these parts, but instead purchase the above kit which includes everything at a better price. But, people have asked, so I have the individual parts listed as well.

I designed these to be nearly an identical replacement, but with the advantages of modern 3D printing technology we can engineer materials that were previously impossible. I printed with NinjaFlex black TPU polymer (https://ninjatek.com/ninjaflex/), which is nearly indestructible (but a knife or scissors will cut it, just like rubber!), flexible, and pretty gripping on most surfaces. 

Basically, the four typewriter feet press and secure the machine on the bottom, and these four "case rubber" parts press down onto the folded metal parts on top of the machine to secure it. The old ones (dried up, missing) likely allow movement and potential damage, whereas I made these to apply slight pressure and compress. Again, 3D printing magic, 30% gyroid fill and a hole on the inside to allow air to compress, so easy to install, they stay in, and compress on the machine when you close the lid.

PS: Ebay's volume discount display is a bit confusing, each purchase is a SET OF FOUR feet, so picking "1" is one set of 4; "2" is 2 sets of 4 (8), etc.