General description An essential tool for routine maintenance on rear brake calipers on BMW MINI, specifically designed to rewind the rear brake caliper on pre-2007 models (R50, R52, and R53). Technical specifications Includes special adaptor OEM No. 34 6 300/301 Includes reaction plate OEM No. 34 6 307 3/8"" drive Special adaptor 21 (available separately - Part No. 3941)