A clamping device which secures a retractor support apparatus to an operating table having a side rail. The product is an aromatic hydrocarbon with ultra-low amounts of nitrogen poisons that can deactivate acidic catalysts. In-band hardware links, which carry both data and control information, are used to connect the controllers and switches in a domain, and thereby reduce the number of hardware links from that used in networks which have separate hardware links for both data and control information. The match insurance itself may be tradeable. The microprocessor is able to receive commands from the external equipments via the communication module, thus, the first photographic device is controlled accordingly so as to take photos.