I just replaced mine, I bought a Hobson powered one form Auto Zone http://www.autozone.com/autozone/parts/Hopkins-Trailer-Tail-Light-Converter/_/N-8ijmg?itemIdentifier=70605_534335_0_
It says it's waterproof but if you mount it under your draw bar like I did it will get water in it and fail, probally because something from the road put a hole in the side of it.