I've been using an earlier version of this on my daily bicycle commute for over 8 years. I think it is a great alternative to a sleeve and has been essential while I'm trying to decide which cover to get and waiting for it to arrive. I usually use it to protect the cover from scratching, but it would certainly protect a bare kindle from chipping.
https://www.bedbathandbeyond.com/sto...tegoryId=12614
I bought it for a K2, but it works great for K4NT and Voyage. The Oasis 2 with cover fits, but barely.
I'd say it could double as a potholder except its shape doesn't seem right for that for me.