Riders looking for a low-profile lumbar pack with integrated hydration need look no further than the Seral 4. The Seral 4 has enough storage capacity for ride essentials, such as a spare tube, CO2 and multi-tool and, of course, snacks. Constructed with high-quality bluesign®-approved recycled high-tenacity nylon with a PFC-free DWR coating. Lumbar Carry: For riders who require hydration or gear storage while riding, but prefer the off-the-back carry and minimalism provided by lumbar packs. Ride Stability: Our bike-specific, angled hipbelt and compression straps provide stability and comfort by keeping the pack close to your body. This is created by a breathable airmesh wrap hipbelt that contours over the hipbone, Ospreys ErgoPull cross-body waist strap closure system that pulls the pack into the lumbar and side compression straps that pull the load close to your body, providing the most comfortable, secure and stable carry. Included Reservoir: A dedicated hydration compartment stores