A Detroit locker, is an automatic locker made by Tractech. The Detroit is probably the strongest automatic locker made as it replaces the carrier and all. Great off road but a PITA on the pavement. Down right spookey in the snow and ice on pavement. There are other automatic lockers that are easy to install of the lunch box type such as the Lockrite and similar if not identical Aussie locker. These are cheaper, easy to install yourself, but not as strong as the Detroit. They suffer pretty much the same on pavement behavior. The best bet is to have selectable lockers front and rear for the best of on and off road worlds. Today your choices are ARB, both front and rear avaliable or the Toyota electric locker, rear only but a different housing so you have to swap the entire axle.