Dynarex Non-Toxic Disposable Plastic 5 x 9 Instant Cold Pack 4518 24 per Case Dynarex instant cold packs are flexible and conform to the contours of the body activating with a single squeeze. Convenient single-use packs provide instant cold therapy for minor injuries making them ideal for first aid kits sporting events schools and home use. Cool temperature last for up to 20 minutes. 24 per Case One Size Fits Most 5 X 9 Inch