The AO 24 Pack Canvas Cooler is a popular size between a small lunch box and a large cooler. The exterior is made from 600 denier polyester canvas with a heavy duty backing for exterior strength, and a Scotch Guard topcoat for UV protection. It is insulated with ¾-inch thick polyurethane high density closed cell foam, which makes it difficult for air to be blown through. It is lined with a leak proof, eco-friendly welded TPU liner that has physical strength and elasticity, making it abrasion resistant. This cooler is popular for boating, picnics, lunch use, and traveling.