Used Ken Titmus RT backbores

Ken Titmus' KTCM mouthpiece backbores are designed for the commercial trumpet player. These backbores feature a unique "reverse taper" that increases air compression and aids in upper register and high volume playing. Condition is excellent, showing only minor insertion marks and minor tarnish to the silver plate. 

From Ken Titmus:

The RT (reverse taper) design produces a resistance which tends to be more predictable and secure at high volume levels. 

The RT1 Lead Trumpet Backbore was inspired by the West Coast “studio” sound. It is small internally. If you are able to play a Schilke A backbore or a Reeves 692sL, you’ll love this one for its firm even resistance across all registers. The bore is #27 at the interface and #30 at the apex. As you overcome the resistance of the RT1 the payoff is in efficiency and projection. Its intense focus makes it ideal for studio recording and miked live performances.

The RT2 Lead Trumpet Backbore is the flagship model of my line. After working with hundreds of lead trumpet players over the years I can say that I have a good idea of what they are looking for in a backbore. That would be a backbore which produces a bright projecting burn in the sound and energizes quickly into the blow. The RT2 is an exceptionally good match with shallow and extra shallow cups, and its high output assists lead players in broadcasting their intentions to the rest of the band.  Bore: 27>29