Auburn Gear's NEW MAX Lock Locker(TM) is an automatic FULL locker, which fits into the O.E.M. open carrier, giving both 4 Wheel Drives AND 2 Wheel Drives optimized traction all the time, even in the most unforgiving conditions. With enhanced transfer of power to the wheels, rapid reaction to changing road conditions and an elimination of wheel-spin, MAX Lock means confidence. Will fit in the front or rear stock open differentials. Basic units currently available. Units with new side gears are coming soon.