Features & Specifications External zip pocket for keys and essentials Secure Bungee Cinch System holds extra clothing Low-profile design keeps pack stable and doesnt interfere with helmet Soft mesh harness is comfortable and breathable Reflectivity for increased low-light visibilityCapacity: 50 oz (1.5 L) Dimensions: 13.5 in x 8 in x 1.75 in (343 mm x 203 mm x 45 mm) Cargo: N/A Weight: filled 4.10 lbs (1.86 kg) empty .80 lbs (.36 kg).