The Five 5ided® Smooth mattress protector helps prevent the development of asthma and features the laboratory-certified H2Pro® liquid-proof membrane on five sides of the mattress. With microscopic pores to allow air passage, the H2Pro® layer completely blocks liquids, viruses, dust mites, and allergens. Unlike other bed protectors is quiet and includes the universal fit elastic ensuring a secure fit for mattress depths 6"-22".