An electric strike includes a housing, a keeper pivotally arranged in the housing, and a holder slidably arranged in the housing. A first pressure receiving area formed by the first valve seat and the valve element joined to each other to receive the pressure of the first working fluid is set approximately the same as the third pressure receiving area of the stem part receiving the first working fluid in the storage chamber. In addition, the disk has a central opening in the form of a hexagon socket. The lighting device may comprise a third plurality of MEMS cells where the operative surfaces thereof is devoid of a conversion coating, or, alternatively, comprises a third conversion coating. A lead reduction mechanism, such as a built-in self-test engine, can be provided on each chip or on the carrier and is connected to contacts of the carrier for the testing and burn-in steps. The articles of the invention may be used, in certain embodiments, to detect the presence of other compounds such as single molecules, proteins, or specific nucleic acid sequences, as well as cells, bacteria, and viruses.