The broken lines in the figures are for illustrative purposes only and form no part of the claimed design. As can be seen from the various embodiments, the design has various levels of abstraction. For example, the front rim of the connector apparatus, the inner periphery, the three circular elements, the three polygon elements, the periphery of the innermost region, and the small inner shapes, numbering ten in all, can be combined together, as in the first embodiment. Additionally, each of these features, either individually or in groups of two or more, can be removed, by being converted to background, for example, in other embodiments of the design.