Circular "audio spots" are placed throughout the museum, indicating where supplemental audio interpretation may be relevant.			The iPods are contained in custom built Baltic Birch cases. A pair of amplified speakers is built into the case, allowing a visitor to choose not to wear headphones if they prefer. This picture is of the first prototype.			Simple operating instructions applied directly to cases help visitors who are unfamiliar with iPod controls. A map of the museum is included as well. The second generation has access to batteries and charging cord.