Manageability tools are provided for allowing an administrator to have better control over switches in a lossless network of switches. The body member defines a battery receiving space and a card slot adjacent to the battery receiving space. Accordingly, the current flowing through the fluorescent tube can be conformed to specificationsregulations. Nodes positioned at points or intersections along the magnetic path have magnetic switches triggering a broadcast of additional information to the user concerning the magnetic path at the triggered node and along any divergent magnetic paths extending from the node. The drive device and the shutter unit are arranged so as at least partially to overlap in a direction orthogonal to an optical axis of the lens barrel.