The FastBack 70LS Hydration Pack lives comfortably just left of center on the back of your seat. It's the solution for lowracers and other hard-shell bikes & trikes with limited tire clearance, as well as Bacchetta EuroMesh seats. Stow away a 3L CamelBak Bladder or some gear. Get the Double Century instead and wield another pack of power! Have a 70LS already? Get the 70LS to Double Century Upgrade Kit and boost your capacity!