YAMAHA Trumpet Mouthpiece John Hagstrom Model

This is the signature model of John Hagstrom of the Chicago Symphony Orchestra.
Its most distinctive feature is a rather deep scoop from the rim to the edge of the cup.
It has an original design where the inner edge of the rim seems to dig into the inner wall of the cup.

Unusually for a Yamaha mouthpiece, the rim, cup, body, and shank have a satin finish,
with deliberately left grinding marks as part of the design.