Osprey Seral 4Minimal Carry for Maximum Flow For riders who prefer ultra-minimalism, the Seral 4 is the answer. This slim lumbar pack carries nothing but the essentials-spare tube, CO2, multi-tool, snacks-plus your 1. 5L Hydraulics reservoir for hydration. The bike-specific fit keeps it close to your body on technical terrain, and the Air Scape backpanel keeps your lower back cool and dry. Perfect for quick trail sessions where you don't need much, just the necessities to keep riding. Features Low-profile design for riders who demand minimal carry Bike-specific angled hipbelt with compression straps for close-to-body fit Air Scape backpanel with lumbar wrap for ventilation and support Included 1. 5L Hydraulics reservoir with magnetic bite valve attachment Zippered main compartment with tool organization for ride essentials Made with bluesign(R) approved recycled materials built tough for the trail SPECIFICATIONSIntended Use Mountain Biking, Light Rides Capacity4 L (plus 1. 5L reservoir)Weight0. 93 lbs / 0. 42 kg (without reservoir)Dimensions7. 5" h x 12. 5" w x 4. 5" d Included Reservoir Osprey Hydraulics 1. 5L Lumbar Materials Recycled high-tenacity nylon, bluesign(R) approved Warranty Lifetime All Mighty Guarantee | Osprey | Seral 4 | Pediment Grey Dust Print | Hydration Pack | Nylon