Park Tool DW-2 Clutch Wrench for Shimano Shadow Plus Derailleurs. Park Tool DW-2 Clutch Wrench. DW-2 is a small thin wrench with 5.5mm and 3mm openings designed to fit the rear derailleur clutch tension adjuster on Shimano XT SLX Deore Saint and Zee rear Shadow Plus (+) derailleurs and all previous Shadow Plus models.5.5mm and 3mm openings