Tri-Core® Water Pillow is an adjustable waterbase pillow for side sleepers or back sleepers that combines the comfort of water with the support of fiber. The recessed, threaded fill port with screw-on cap prevents leakage. This unique Tri-Core water chamber, which is removable, has an oval shaped center which displaces the water to cradle the head and support the neck in a more natural position. For convenient laundering, simply remove the water chamber and toss the pillow into washing machine. Helps reduce water movement and sloshing sounds; helps reduce strain on the neck by preventing the water chamber from bulging or doming when filled. For convenient laundering, simply remove the water chamber and toss the pillow into washing machine.