This set of NatraCure Replacement Gel Packs is designed to work with all sizes of our Cold Therapy Socksand Cold Therapy Compression Socks. Full Description As each treatment ends, your Cold Therapy Socks will return to room temperature. Use this set of extra gel packs to extend the duration of your treatment. The full-foot length gel pack is designed to sit below each foot. For added relief, there's an additional half-size gel pack that can be placed either over the toes or behind the heel. Store in freezer or refrigerator inside of cold therapy socks or in a plastic bag May also be heated in microwave for heat therapy treatment as needed Additional instructions printed on gel packs Features & details 4 Piece Set: 2 full-length and 2 half-size replacement gel packs for NatraCure Cold Therapy Socks.