The ARB Air Locker is the best method of attaining 100% locked differential traction for off roading while still maintaining the stock handling characteristics on the street.  Utilizing a 12-volt air compressor (sold seperately), the system is designed to activate (and deactivate) a locking mechanism in the differential which allows the differential to be fully locked or fully open at the flip of a switch.  It is manufactured from the highest quality materials and tested in the most extreme conditions.  Let ARB take you where you want to go.