The Maxpedition Rollypoly Extreme is now available at Military1st.co.uk... "The Maxpedition Rollypoly Extreme is a clever foldable backpack featuring spacious main compartment with hydration sleeve for up to 3L water reservoir, 2 front organiser pockets, adjustable shoulder straps with hydration tube and MOLLE loops, and quick-release sternum strap with built-in emergency whistle.