The Mediflow© is the only pillow clinically proven in 3 independent studies to improve your sleep and reduce neck pain. So your head and neck can enjoy the same comfortable, pressure-free support provided by expensive water beds. Invented in Canada and already used by 5 million people worldwide, its internal water-filled membrane provides constant support for your head, responding continuously to your ever-changing sleep position. Meanwhile, a 12.7cm layer of super-soft polyester floats over the water chamber to add luxurious extra comfort. To make the pillow firmer or softer, simply add or remove water to achieve your perfect customised comfort level. In a clinical study undertaken at the renowned Johns Hopkins University, the Mediflow© was ranked best pillow not only for reducing neck pain, but in all 5 sleep-quality categories tested.