An outer enclosure may comprise a first enclosure region defining a first enclosed space and a second enclosure region defining a second enclosed space. The first enclosure region may comprise a first opening edge, and the second enclosure region may comprise a second opening edge. The first and second enclosure regions each have an inner surface. A first inner arm enclosure region may be secured to the inner surface of the first enclosure region and, together with the first enclosure region, defines a first arm passageway having a first arm entry opening. A second inner arm enclosure region may be secured to the inner surface of the second enclosure region and, together with the second enclosure region, defines a second arm passageway having a second arm entry opening.