What are these AV Leads for my TV Tuner Card?

The Antenna-in (Coaxial Input) is used to connect the TV Source, be it antenna or cable. The extra cables are needed to facilitate video capturing from an external source (S-Video or RCA Composite plus Audio). The attached picture shows how, by punching an extra hole in the bottom I/O sheet metal plate, the connectors can be made accessible. This is only if the unit did not come with the AV Leads already accessible.