I purchased this item because it is supposed to be a hypoallergenic, waterproof, mattress cover. It has a zipper so it would encase the mattress.  It has a zipper, and it encases the mattress, but only the top is protected.  The rest is a stretch mesh.  I'll try it, but I have others that truly wrap and protect the entire mattress.  This cover ​is not all there.