This is a right angled AV f-plug adapter.
It converts a standard f-plug (which you find on aerials, satellite boxes etc) into a right angled plug. It is great for any equipment that needs to be placed close to a wall. The adapter reduces strain on cabling by eliminating and sharp bends in the cable, this means the working life of the cable should be significantly increased.
The adapter connects quickly and easily to the end of any standard f-connection.