Osprey zealot 15 backpack by definition a zealot wants it all everything so why not own the mountain we went about designing the zealot 15 in exactly the same way youd look at your next descent what limits could we push the need to have features and durability but remain lightweight and comfortable zero compromise riding fast means the slightest movement has an effect relax knowing our airscape backpanel with tri section ridge foam provides relentless ventilation and support the biost