A great mattress is usable for a long time and this mattress encaser helps to protect your mattress so you can use it longer. A bug block zipper prevents bed bugs from making your mattress their home. Stain protection helps prevent dust mites from clinging to the encaser. The encaser even protects against bacteria through its breathability. What this means is air passes through more easily, water can evaporate more easily and bacteria don''t find it as easy to live.