ULTRA SLIM 275 design is perfect for back and stomach sleepers helping to alleviate neck pressure DoubleSided Washable Pillowcase Featuring cool ice silk fabric on one side and soft breathable lyocell knitted fabric on the other side Couples or family members can choose their preferred side based on their habits Ventilated Foams The breathable holes enable maximum air circulation enhancing comfort and when assisted by the cooling knitted fabric cover it extends the feeling of coolness CertiPURUS Certified Memory Foam No harmful chemicals more friendly to human body and environment WHY CHOOSE HCORE We are dedicated to improving peoples deep sleep and in pursuit of this goal we have created a collection of proprietary foams and products that provide great support and reduce motion transfer to offer more restorative nights sleep