At one point in time the Boston Pops Esplanade Orchestra horn section was all playing the Conn Geyer wrap horns (10D and 11D).  They are a great 'bang for the buck'.  Conn decided to expand its 'audience' from the 8D to the Geyer realm and these were the horns that they introduced.  They were an immediate success.  This one is made of lacquered yellow brass with a fixed bell.  The compression is great at 1.1.  It is in almost perfect condition and is FAR below the cost of a new one.  Everything is original on this horn.  The fingerhook is adjustable, and it can easily be set to stand in Bb if desired.  The 11D'E' is the updated version of the 11D.