WARNING: This page is about a different car, the 2013 BMW 550i GT, 2012 BMW 550i GT, 2011 BMW 550i GT, and 2010 BMW 550i GT. However, it is still accessible from the selected car via links, so may be relevant.
0491366 138025 Adapter MW
NOTE:
(Adapter hose) With quick-release coupling and ring connection with banjo bolt for testing the output pressure at the metering unit [Discontinued]