The ultimate body comfort. All of Bucky's hot and cold therapy/spa products use premium whole buckwheat seeds. They are recommended by professional spas and salons because they retain a gentle, moist heat, are naturally fragrance free and hypoallergenic. All covers use a soft and plush fabric that is removable and machine washable. Use heated...microwave for penetrating warmth to reduce tension and anxiety, stiff and sore muscles, aching joints, headaches and arthritis pain. Makes a toasty bed warmer too! Use chilled...chill in the freezer for a refreshing cold pack to sooth strained and sprained muscles, bruises, insect stings, hot flashes and reduce inflammation and swelling. It's also easy and refreshing cooldown on a hot summer day or after a workout. To view more of our spa and travel products visit amazon.com/Bucky.