The 14-1-2 has a slightly smaller backbore than the 14-0-2.  The bore size is 14 while the external taper is .293"/7.442mm at the tip.

The Houser "San Francisco Model" is used by the horn section of the San Francisco Symphony and is based on the time-tested, bowl-shaped cup design that has been found to be most compatible with Geyer-style horns. Its design can be traced back to mouthpieces made by Carl Geyer himself and offers quick response and evenness throughout all registers. It provides a rich, complex tone in lower dynamics and plenty of brilliance and projection when played loud. This allows the player access to a wide variety of tone color possibilities without sacrificing response and flexibility.