we had one in the front of our toy axle that was in our old sas kick, it was GREAT! also, customer service, get this, we bought the locker new used, but used none the less, and we had problems installing it, so i gave them a call and they sent me out a NEW one.
turns out they are so beefy, that they don't always fit in all toy carriers without a bit of machining.
but ya, to bad they dont make ones for zukes.