MicronOne® Patented Waterproofing on 4 sides; top, bottom, left and right sides. Protects your bed from allergens, spills, incontinence, bed bugs, mold spores, bacteria, virus, and normal wear-and-tear. Zip-N-Click, our patented self-locking zipper enclosure snaps shut to block bed bugs and prevent accidental openings. Easier to use and more secure than zip-ties or Velcro flaps! Air permeable fabric on the short ends allow warmed air to escape the mattress to prevent the feeling of a “hot bed”. Don't wait, order yours today!