Whether you are walking the Four Days Marches, taking a nice bike ride or going to the office... The deuter AC Spider 20 is the perfect backpack for every occasion! The Aircomfort system provides maximum ventilation and optimal freedom of movement. The mesh frame creates an effective ventilation space between your back and the backpack, allowing the warm, moist air to escape through three sides and keep your back pleasantly dry. Additionally, the backpack is provided with a hip belt, an upper compartment, a removable bottom compartment, two mesh side pockets and an elastic webbing on the front for quick storage of your sweater or fleece jacket. This deuter backpack is without a doubt your perfect companion during the Four Days Marches!