These are serious coolers designed for extreme adventure or even just when there is a lot of stuff to keep cold and it's not desired to lug a huge, hard, bulky cooler around! The seams are rated to 65 pounds, and there is a padded, ventilated backpack strap system, this is absolutely the world's most portable HIGH-CAPACITY, high-performance cooler. It is available in three sizes - Large (20L), X-Large (30L), and XX-Large (40L).