I wanted something to protect my memory foam mattress from getting mildewy. Nothing on the package says anything about water resistant. I'm assuming polypropylene inherently 'water resistant' and wayfair extrapolated that feature. Otherwise I guess it's keeping the bedbugs and dust mites out of my week old mattress? 

Its fine.

(optional) Example: Great value, easy assembly, durable finish
(optional) Example: Not enough color options