An essential tool for routine maintenance on rear brake calipers on BMW Mini. The set includes the special adaptor OEM No. 34 6 300/301 and reaction plate OEM No. 34 6 307.Special reaction plate (OEM No. 34 6 307).3/8″D.Complete with special adaptor 21 (also available separately – Part No. 3941) (OEM No. 34 6 300/301).Designed specifically to rewind the rear brake caliper on pre 2007 models (R50, R52 and R53).An essential tool for routine maintenance.