Z takes the natural benefits of GEL DOUGH memory foam and adds Zoned Technology to create the perfect combination of cooling comfort and support. Z's Zoned Technology utilizes pin-cores that are configured to cradle your head while providing your neck and shoulders with needed support. Simply stated, there are two comfort zones in this pillow. The center of the pillow has larger holes to allow your head to sink into the pillow with optimal comfort, while the outside of the pillow uses smaller holes to support your neck and correctly align your spine. These pin-core holes have the added benefit of increased airflow. DOUGH memory foam is infused with cooling gel material , to create GEL DOUGH, a softer, cooler, and doughier memory foam. The addition of the Zoned Technology provides exceptional airflow making it one of the coolest, most breathable pillows available today and will help you get a cooler night's rest. Accompanying this pillow is a luxuriously soft and breathable cover made of rayon from bamboo velour (75% polyester, 25% rayon from bamboo.) Rayon from bamboo is excellent for sensitive skin and is a great temperature-regulating fabric. The cover is removable for laundering, helping you to create a healthy sleeping environment. The 5-year warranty protects the pillow and cover from manufacturer defects.