We designed a backpack that would stay colder and hold Ice longer than anything on the market. Our backpacks have 50% more insulation than its closest competitor. Our zippers are twice the size of other backpacks. Zip in liner that is environmentally friendly and also food grade with welded seams. Also If for some reason you damage the liner we can provide a replacement. IDB's backpack also has many compartments for your keys,wallet and sunglasses. Whether your hiking or just going to the beach or maybe even going for a day sail I think you will find that IDB's backpack will replace that bulky cooler you use to take. Size 15"H / 9"D / 12" W