The Schnellkuppler is a trailer aid and anti-theft device for caravans, towed caravans, horse trailers, trailers and car trailers. This allows the trailer to be coupled easily and quickly, the trailer coupling to be secured and fitted with an anti-theft device. The Schnellkuppler fits into any European trailer, so that even caravans with an anti-slinger coupling can be fitted with anti-theft protection and the coupling aid. The additional trailer lock serves as a drawbar lock and anti-theft device for the car trailer. Trailers, caravans and horse trailers with tarpaulins and support wheels can use the Schnellkuppler to secure the trailer coupling and couple the trailer without damaging the bumper of the car. This enables the driver to avoid impact damage and paint damage and to attach the car trailer safely and easily to the car. The Schnellkuppler is on the one hand an accessory for car and car trailers, but on the other hand also counts as a car part, since its anti-theft device serves both as a lock for the trailer and as anti-theft protection for the Schnellkuppler. In addition, the Schnellkuppler makes it possible to couple the car trailer alone, quickly and safely. Even for inexperienced drivers, the car trailer is easy to tow. Because the Schnellkuppler offers due to its catching shells made of metal, the solution to the trailer coupling, since ball coupling and trailer coupling are led over each other. The operation of the anti-theft device with safety pin and lock as well as the coupling of the Schnellkuppler is simple, safe and fast. The Schnellkuppler does not represent any technical changes or interventions in existing systems and can therefore be used carefree as a coupling aid for trailers, caravans and horse trailers.