Suitable for all European standard trailers. Establishes a secure connection between your major vehicle and the additional trailer. Transfers the electronic signal lights from the vehicle to trailer. Converts the 7-pin male socket to the 13-pin female socket on your trailer. Slim line design: same diameter as a normal trailer plug and just over half the length. Excellent quality black plastic housing helps prevent rusting. Simple to fit. Waterproof for all road and weather conditions. Carries the European CE mark of approval, do NOT buy adaptors unless they have this endorsement.