A tape drive has a microswitch, with a microswitch plunger, that interacts with a tape cartridge having a recess therein that is selectively closed or opened by a sliding element movable back and forth in the recess, to detect whether the recess is opened or closed and thus to enable or disenable a data transfer function between the tape drive and the tape cartridge. The tissue can have an elastin content and the elastin can be chemically fixed using a phenolic tannin, for example, tannic acid. In zooming from a wide-angle limit to a telephoto limit at the time of image taking, at least the first lens unit and the second lens unit move in an optical axis direction, while the fourth lens unit and the fifth lens unit are each consists of one lens element. That port may be used to introduce catheters or other instruments into the body cavity. A third actuator is movable between a fifth position, contiguous with the third location, and a sixth position, contiguous with the fourth location. The mattresses are preferably displayed at the point of sale location restrained in a compressed state having a reduced volume compared to the expanded state, which preferably reduces the amount of space occupied for the display unit.