The Seral lumbar packs are perfect for the mountain biking minimalist. Supremely stable for laps on local singletrack or gravel trails, this off-the-back hydration solution provides carry for a few key essentials and water. The Seral Series includes a lumbar reservoir.Key Features:AirScape backpanel with contouring lumbar wrap provides maximum stabilityIncluded Osprey Hydraulics 1.5 L lumbar reservoir by HydrapakMagnetic hipbelt bite valve attachmentLarge zippered main compartment with reservoir sleeveMain compartment tool organisation and internal zippered pocketLED light attachment with reflective graphic