100% CottonLOWER YOUR BODY TEMPERATURE WHILE YOU SLEEP – Place this gel pillow protector under your pillowcase, and the gel will absorb your body heat and radiate the heat out. Utilizing the theory of thermodynamic equilibrium, this pillowcase will help keep your body temperature down to the surrounding room temperature all night long.GREAT FOR LIGHT SLEEPERS – One major advantage to this cooling pillow protector is that it does not use electricity and is silent. Great for light sleepers and those who like a quiet room and are even bothered by the quietest air conditioners.ENJOY THE COMFORT OF MEMORY FOAM WITHOUT THE HEAT – A chief complaint of memory foam pillow owners is how hot the sleepers get because of how much body heat memory foam retains. Adding a cooling gel to memory foam can only do so much. Don’t double down on a memory foam cooling pillow when the memory foam is what is retaining the heat in the first place! Enjoy your memory foam pillow by using this cooling gel pillow protector without sacrificing the comfort of the pillow!COMBINE WITH COOLING SHEETS, AIR CONDITIONING, AND COOLING BLANKETS FOR BEST RESULTS – When used in a cooling bedroom system, this cooling pillow protector will drastically help reduce your body heat and help you sleep better.SATISFACTION GUARANTEED – Offered with a 30 day sleep better guarantee.