In order to run dual calipers for a hydraulic hand brake with an independent reservoir master cylinder, this bracket allows you to adapt 2 piston Z32 twin turbo calipers to E36M3 312x20mm rear rotors. Installs on the removed drum parking brake's mounting provisions in E46 & E36 non-M trailing arms. NOT compatible with 330ci trailing arms. Must be paired with Z32 foot brake caliper and brackets sold separately. CNC aluminum with gold anodizing, laser logos, and 12.9 grade hardware. Pair with our reproduction calipers, hydrobrake & hard lines and fittings set, all sold separately. Drum parking brake must be removed.