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.