12-1/4" x 3-3/8" Left Hand Electric Brake Assy w/ 5-Hole Cast Backing Plate for Certain Imported Axles Left-hand 12-1/4" x 3-3/8" electric brake assembly Cast backing plate with 5 hole mount Auto adjusting electric brake assembly keeps the brake adjusted Completely assembled, ready to install This electric brake assembly is NOT used on Dexter axles. It is found on trailers with imported axles. We have seen it used on trailers made by Quality Trailer, H and H Trailer, J and J Trailer, and Lippert Trailer. There are sure to be other manufacturers using this brake that we havent yet identified.