GR Haefner 1HX Signature Mouthpiece
This is a Gary Radke, Steve Haefner Signature mouthipece with the #3 backbore. It has a generous semiflat rim with a strong inner bite (rim similar to a Bach 1X)) The diameter is 0.67 in. The cup is v shaped, with a volume of .871 cu in. It is in great condition.