Those are the female contacts that are inserted into a housing for constructing a custom connector. There are insertion and removal tools available for these, and if you're careful, you can make your own. Often, insertion is a simple push-it-in-with-your-finger operation. Removal requires a thin, hollow tube that will fit between contact and housing to push those wings in toward the contact body so you can push the thing out. Check out the AMP or Amphenol web site or one of their catalogs.
they're connector pins. the pogo pin sockets are usually gold plated, have a wire wrap pin on the end opposite the opening, and only have one flange at the open end so they seat nearly flush in a fiberglass panel