The BatWing track connector is used to connect track section ends together. Spares are shipped with original SuperTrack orders. This can be used to replace lost connectors.
The original SuperTrack used flat, glued-in connectors. If they come loose then the BatWing connector can be substituted. If BatWing connectors are glued-in (not recommended) be sure they do not make the complete assembly so long that it will not fit in the box!