UHF coaxial and 'F' type connector on an external waterproof socket.  Comes with 3m of coax cable and connectors.  Drill a hole to put the coax cables through and stick socket onto the side of your motorhome or caravan with supplied double sided pad and/or screw to the side of your caravan or motorhome.  Enables you to connect an external aerial and satellite dish without having to route the coax cables through a window or door.