Seral 4 Lumbar Hydration Pack Description: The Osprey Seral 4 Lumbar Hydration Pack is perfect for the minimalist looking for something other than a traditional over-the-shoulder pack. The Seral features a dedicated hydration compartment that stores an included 1.5L lumbar reservoir and compresses for stable carry. A dedicated hose magnet attaches to the bite valve for easy access. Features: Easily accessible zippered main compartment with internal tool organization Direct access zip path to reservoir compartment Magnetic hip belt bite valve attachment Hydraulics 1.5L Lumbar Reservoir included Extra thick ridged foam with center air channel for excellent ventilation Airmesh wrap hip belt with zippered fabric pockets provide stability and breathability Light attachment point and reflective logo add safety in low light situations Specifications: Pack Type: Hip Pack Pack Capacity: 4L Reservoir: Included Reservoir Capacity: 1.5L (50 fl oz) Bike-Specific Design: Yes Helmet Mount: - Gender: Universal Dimensions: 7.5 x 12.5 x 4.5" (Height x Width x Depth) Color: Blue Weight: 443g