Stabilizer-coupling

The invention relates to a trailer coupling for coupling to a towing ball (6), comprising a coupling housing (1), first and second coupling members (3,7) which are arranged in the housing and which comprise hollow friction-coupling surfaces directed toward each other, wherein at least one of the coupling members (7) is mounted in the housing for sliding between an open position at a distance from the other coupling member and a closed position closer thereto, wherein the slidable coupling member (7) is connected to the housing (1) by two arms connected pivotally to each other, which arms lie substantially mutually in line in the closed position, and wherein a connecting arm (15) is arranged between the arms and an operating lever (10) connected pivotally to the housing.