Add water once to our science-based powder formula, zip and seal with iron, then freeze for your next outing. Cooler Shock packs are high performance, long lasting, and reusable. This premium ice pouch is made with multi-layered aluminum and polyethylene to keep the contents secure and reinforced with thin nylon to help strengthen the pack. These large durable ice packs can keep your cooler at 18 °F for up to 48 hours depending on use. Cooler Shock is a large cooler ice pack that replaces ice in your cooler for camping, fishing, boating, travel, catering, and farmers markets to keep food and fish fresh. They are great ice alternatives and ice extenders. They work great in Yeti, igloo, and other large coolers as well as soft side coolers. They are also used to transport food or drinks and baby milk while traveling or camping. They outperform Yeti ice packs, Blue Ice and Nu Ice. Works great for keeping your beer and drinks cold all day.