Decrescent Universal Schuetzhuelle ...

I bought this case for my "old" Kindle the end of February this year.
Then cost EUR 5.49 incl. Shipping from Jersey. My eReader comes with me through thick and thin - that is, tropical beaches and humid leaving jungle camps, sand dunes of all kinds, air mattress or bath and beach parties ...
No problem for this waterproof, sand proof and also against splashes absolutely tight envelope.
In August my daughter has the good part borrowed for your new Kindle Fire, which is also used by the youngest members of the family, 4,5 years old, for your holidays in Sardinia. And only very reluctantly returned.
Noel sun, sandy beach, splash any kind, including Coca etc. - the part kept everything off!
And at the price!
I'm going to order two more Cases before the price continues to rise :)

Have fun in the tub or on the beach!