Taking full advantage of the Siletz' 35 Liters of water-tight storage is its incredibly versatile suite of complimentary modular accessories. The full range of accessories are organized into two separate, integrated accessory systems that we painstakingly designed to help you seamlessly transition between the various aspects of your life. The components of each system are designed to slide effortlessly into the Siletz and work in unison. The Cooler Insert is part of the Outdoor System and integrates simultaneously with the Night Bag/Gear Pouch and Wet/Dry Insert within the Siletz 35L Waterproof backpack. Designed to carry a full lunch, or a six pack of your favorite beverages with ice, the Cooler Insert slides down nice and snug within the Siletz 35L and keeps your food and drinks cold for 48+ hours. An airtight and watertight TIZIP® zipper keeps moisture in or out and 1” thick closed cell insulation does all the hard work to keep things chilled. A carry handle and shoulder strap also allow the Siletz Cooler Insert to work well as a stand-alone cooler outside of the bag when nothing else needs to be carried.