Osprey Seral 4 Lumbar Pack

With 4 liters of carrying capacity, the Osprey Seral 4 Lumbar Pack is the optimal size for the vast majority of mountain bike rides. Equipped with a 1.5L hydration reservoir, a big zippered main compartment with internal organization for bike tools, and Osprey's beloved AirScape lumbar backpanel for ergonomic comfort and ventilation, the Seral 4 Lumbar Pack is just what you need to focus more on the trail and less on combating sweaty back syndrome.