MSR (Mountain Safety Research) Fuel Bottles are made from a single piece of impact-extruded aluminum to prevent leaks and cracks. We've designed the bottles with thicker aluminum at the bottle's base and shoulders to resist bulging when pressurized. Holes in bottle cap shaft allow a measured flow to prevent spills. Air-tight seal allows fuel to be stored longer by preventing air from entering and degrading fuel. MSR's Fuel Pump is designed to fit inside a depressurized fuel bottle for ease of transport. Extruded aluminum Thicker at base to resist bulging when pressurized Air-tight seal Volume & Weight with cap: (22oz/650ml) 4.9oz/139g (30oz/887ml) 7.3oz/207g. 22 oz. Manufacturer model #: 11831. 30 oz. Manufacturer model #: 11832.