Sky's makes one for the Toyotas, and Spidertrax makes one for the Samurai, but I haven't seen one made for RBVs yet, probably not popular enough to profit from it. My LJ came with a drum brake version, and I know the SJ410 came with something similar, it wouldn't be too hard to make something, if you go to Sky manufacturing, you can see the kit, and basically how it works. You may be able to adapt their kit to be made to work on the RBV, but it may be some work, as it bolts up to the toyota transfercase. The only downside to these, is if your rear driveline breaks or is removed, you have no E-brake.
