Recommended by Chiropractors to maintain spinal alignment during sleep. The secret is the triangular-shaped buckwheat hulls that conform to bodily contours and interlock to support head and neck, providing much-needed relaxation of neck and shoulder muscles during sleep. Hidden zippers adjust level of comfort. Vegan, hypo-allergenic, chemical-free, eco-friendly. Helps support American farmers. Filling does not bunch or clump and lasts for years.