Our 5-Sided Mattress Protector provides top and side mattress protection. The OmniPhaseTM phase change material actively regulates temperature by absorbing and dissipating heat, and the TencelTM Lyocell fiber aids in optimizing sleeping temperatures as it's known for its superior moisture-management properties. This proprietary fabric combination provides all-season comfort. In addition, the quiet and breathable laboratory-certified H2ProTM membrane is liquid-proof and dust mite-proof. The fitted sheet design features Universal FitTM elastic that ensures a secure fit for mattresses with depths between 6 and 22 inches.