GR: "The WB Studio M Model is the very best of innovation and the ability to apply GR's design technology with any diameter or set of parameters. The same slightly lower alpha angle that is used on the WB Classic Model mathematically balanced with the GR's popular M cup. Simply a WB M cup with a #2 backbore giving that signature GR sound that has become a paradigm in the industry. Wayne really needed this addition for his vast work load."

Specs:
Backbore: 2
Cup Volume: 0.0733 Cubic Inches (Medium)
Cup Diameter: .631 Inch
Contour: Semi Flat-Wide
Bite: Soft
Alpha Angle: Medium High