Trailer coupling

The motor vehicle trailer connection has a connecting arm (9) with a ball for connection to the trailer at one end. The other end has a rotary pivot axis (10) mounted in the hitch housing (1). The arm has a pair of locating shoulders to engage the housing sidewalls and a partially cylindrical section between forming a wedging face defining a shield shape in plan view. The wedge face can selectively engage a corresponding cut out in the housing and lock the connection.