This is the flexible rubber brake hose for the right hand rear caliper.  this one runs along the rear trailing arm and is the inner (shorter) hose of the two.  The outer hose is CD6248.  These two hoses have been known to swell and block internally and are the most common cause of a brake caliper sticking on and overheating. 

1966-1980 Silver Shadow, T-series, Shadow II, T-2, Corniche, Silver Wraith