The Relief Pak re-usable cold pack is an effective method of applying cold therapy to localized areas. Place the Relief Pak Cold Packs in a chilling unit or freezer. Relief Pak Cold Packs remain pliable and soft even below freezing. Cold Pack maintains its therapeutic level for up to 30 minutes. Relief Pak Cold Packs can be wrapped with a light towel or Terry Cover and applied to the treatment area. Size: Oversize Cold Pack 11 x 21"