Minimization of delay due to automatic repeat requests in a multi-hop communication system can be accomplished to optimize the performance of delay-constrained applications such as voice over internet protocol. In a particular aspect of the invention, a source of microwave radiation is provided proximate a reaction chamber. In the body, the area of the panel corresponds to a window formed in the rear surface, the looking-out portion of the projection overlaps with the finder, and the drive unit is arranged in a side of the finder. In another embodiment the present invention provides a novel search inputoutput interface that displays andor communicates search input criteria and corresponding search results in a way that facilitates intuitive understanding and visualization of the logical relationships between two or more related concepts being searched. A wrench tool that can be quickly changed to different sized wrench openings sized to fit hydraulic, oil, and water and fuel line fittings, generally known as AN fittings. The front side of the glass substrate includes a region where the cavities used to house electronic devices such as semiconductor IC chips and crystal blanks are not formed.