Shimano RD-M8250 Deore XT Mounting Screw Unit Description: The Shimano RD-M8250 Deore XT Mounting Screw Unit is a factory replacement part that is designed to attach select Shimano Di2 rear derailleurs to the derailleur hanger. If part of the stock mounting screw on your derailleur has become damaged or has gone missing, this part will restore the ability to properly secure the derailleur to the frame. Features: Designed to attach select Shimano Di2 rear derailleurs to a derailleur hanger Each order will include: (1) Mounting Screw (1) Screw Sleeve (1) B-Screw Limit Plate (1) C-Clip (1) Thin Washer