evo.com | Osprey Hydration Packs > The Osprey Siskin 12 Hydration Pack has everything you need to make the most out of your next mountain bike adventure. Featuring a super breathable mesh back panel and a 2.5-liter reservoir so you can stay cool and refreshed, the Siskin 12 also incorporates a tool pocket for quick repairs and the LidLock attachment system that accommodates a full face helmet. Main 900x600D Polyester Osprey Hydraulics(R) LT 2.5L Reservoir by Hydrapak 18.5 H x 9.1 W x 8.7" D Full Front Panel U-Zip to Main Compartment and Tool Organization Variable Helmet Carry Includes Osprey's LidLock helmet carry for traditional helmets and front panel upper compression straps for full face helmets. | Osprey Siskin 12 Hydration Pack 2026 in Blue | Polyester