A rotary mechanism includes an accommodating slot structure, a supporting arm, a pivoting portion and a resilient component. The transmitter comprises a plurality of transmit antennas for transmitting the signals, which comprise respective independent streams of symbols. Such fibers may be metallized in their individual state and then formed into a fabric, or these materials may be formed into a fabric and then metallized or a combination of both metallizations may be used. Removal of the obstructions enables the catalytic inserts to be pushed out of the flow channels when they are spent.