The Tri-Core pillow is prized for its effectiveness in correctly aligning the spine and supporting the neck in its natural position to help relieve headaches and neck pain for side and back sleepers alike. Because the cervical curve is supported in its neutral position, using Tri-Core pillows helps to correct nerve malfunction and promotes healing of injuries. More importantly, Tri-Core pillows promote good health while providing maximum comfort by preserving the normal curvature of the neck and spine. Chiroflow Waterbase Pillow has a Layer Of Super-Soft, Hypo-Allergenic Dupont Polyester Fiber Floats Over Top Of The Water Layer, & Provides Outstanding Comfort. A Water Pouch Secured to The Base Provides Head & Neck Support.