A dual pocket or envelope for CDs or DVDs is formed of two standard letter size sheets of 8\xbd\u2033\xd711\u2033 or A-4 size paper, which are bonded together around the edges of the sheets and centrally to divide the sheet assembly into two pockets which are substantially square to hold the discs. The present invention provides an air injection adaptor for coupling between a filter tank and a valve controller. Transition metals and lanthanide metals compose the compound from which the interstitial metal hydride is formed. The control circuit can perform a short-circuit failure countermeasure program operation. The wiper blade is reciprocally movable between a first position and a second position over a clearing path, which is disposed adjacent the distribution outlet. Upon flowing the liquid or gaseous sample containing the target through the tube, the target bind to the capture agent and is detected by the amount of light or the variation of its properties while guided through the tubes.