in correction to moezer, no, a one way does not work like locking the rear diff. that is achieved by a solid spool, a ball diff or of course, locking the diff. the one way would act like a handbrake when u get off the throttle. it locks the rear tyres, making the car achieve bigger drift angles more easily. it is something many people like to use but many dont as it is a b**** to learn to use as the car will be a whole new beast to master. if u do have the patience to learn how to use, it would be a great asset as it helps u recover from understeer and also do longer sweeping angles that look even cooler