Never really seen one before so I don't know exactly what this diff is. It is definatly not an open or a 2 or 4 pinion posi. No shafts to hold the side gears. Another strange thing is they resplined some stock 31 spline axles to 28 when they narrowed the axles. Also has 4.86 gears which I might have to change out. They seem a bit much, but whe'll try them with the big 29 inch tire. Thanks for the help.