WARNING: This page is about a different car, the 2013 BMW X5, 2012 BMW X5, and 2011 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
(Pressing-in tool) for pressing in the shielding caps on both sides in the fixed caliper shafts - brake piston diameter 54 - 57 mm/single-circuit brake system