Designed for discerning mountain bikers looking for a do-it-all pack, the Osprey Siskin 8 Hydration Pack provides a stable, breathable, and highly comfortable carry. A next-gen reservoir provides plenty of hydration for your biggest rides and features like a separate main compartment and LidLock helmet carrier give it all-day versatility.Manufacturer model #: 10005101. Breathable and comfortable Next-gen reservoir provides plenty of hydration Separate main compartment LidLock helmet carrier