3 products Ringfeder® trailer coupling RF50 B NZ MSD This strong and reliable 320 kN coupling is designed and built for trouble-free extended heavy-duty use under the tough road conditions in New Zealand. The self-closing and automatically secured coupl... Ringfeder® trailer coupling 5050 B NZ MSD This coupling is ideal for medium and heavy transportation and works with hinged drawbars as well as centre axle trailers with rigids, or dollies with 50 mm drawbar eyes. Its solid and well-tried cons... Ringfeder® trailer coupling 2020 A simple, yet reliable coupling for light transport applications.