Yamaha 30-GP mouthpiece for french horn, inner diameter 17,08mm, rim contour: standard, cup depth: standard (double cup), throat: 4,40 mm, backbore: semi-narrow, silver plated with gold plated rim. Smaller inner rim diameter than the 31. All-around type. Shallow "U" cup facilitates high notes, while a deep "V" makes low notes easy.