This is a Berg Larsen 105-0-CF tenor mouthpiece and was originally a 110-0-M. The piece was refaced by Doc Tenney and has a brilliant or bright tonality, is consistent across all registers and is great in the altissimo range. This piece would work well for a Rock and Roll or Rhythm and Blues player.
In regards to Doc Tenney’s mouthpiece designations, CF stands for “Custom Facing.”