The Chiller Medium Ice Bag is leak-proof, hand washable and great for reducing pain and inflammation from injuries or muscle strain. It is crafted from a pongee fabric for inner lining and a durable, soft polyester exterior that gives a gentle application. The wide-mouth opening with a screw-on cap fits ice cubes, crushed ice or cold water. For warm therapy, fill with hot liquid at or below 140 degrees F. Holds up to 16 oz of liquid. Keeps warm for up to 30 minutes and cold for up to 1 hour.