Satin-type or cotton fabric approx. 8"x4" filled with our lavender buds and flaxseed which allows a balanced weight to the pillow and a good temperature distribution. Comes with an instruction card explaining the uses with microwave or freezer and the possible applications of the pillow. Warmed up, it facilitates pain and ache relief, and cold, it soothes you out of migraines or headaches. Can also be used as is for relaxation and sleep inducement. Lasts for years.