Erik Greiffenhagen
"Double Chamber"
Bari Sax Mouthpiece

Marked .105, I measured it at 0.110". It is probably somewhere inbetween.

$350

These mouthpieces were made by Erik Greiffenhagen using Vandoren V5 B75 mouthpieces as 'blanks'.
Those V5 bari mouthpieces go for about $200 new.
The chamber design has aided in taming some vintage bari sax intonation problems.
HERE is the JunkDude webpage for these mouthpieces.
As you can see in the photos, it is marked "eg" for "Erik Greiffenhagen". [Disregard the circular thread in the photo.]
And also please disregard the small circular red thread in these two photos ( FIRST ONE and SECOND ONE) which show the moderately light tooth wear to this mouthpiece.