Cusco limited slip differentials for professional motorsport use. These are definitely not the cheapest, but are top quality products which are also fully serviceable.
The Japanese Cusco differentials are a true royal member of the LSD family. Cusco is a pioneer in their products. Cusco is definitely not the cheapest, but has been proven and tested in competition and offers cutting edge technology. Cusco is mainly available for Japanese cars like the Nissan Skyline and 200sx as well as the Toyota Supra.