The Five 5ided® Pillow Protector with Tencel® + Omniphase® is the most advanced pillow protector on the market with three incorporated technologies Tencel®, Omniphase®, and the H2Pro® membrane. Omniphase® phase change material promotes a comfortable sleeping temperature in any climate; Tencel® fiber wicks away moisture from the body and the laboratory-certified H2Pro® liquid-proof membrane creates a quiet, and breathable barrier against allergens and dust mites. The combined benefits of these technologies means you will sleep comfortably through the night.