Schilke

SH-II
The Helleberg SHII is made along the same lines as the 66,67, and standard Helleberg. It has the same Helleberg-style cup shape with the same inside diameter as the 69C4 (32.76 mm), a slightly tighter throat and standard backbore.

SH-IIF
The Helleberg SH-IIF has the same rim as the Helleberg SH-II but with a shallower bowl-shaped cup to accommodate the smaller F tuba. The throat is smaller than the SH-II. The backbore is slightly larger, similar to a Schmitt shape that opens up quicker under the throat to reduce resistance.

GEIB
The Geib model has the same inside diameter as the Helleberg SH-II with a modified rim contour. The Geib cup is more bowl-shaped and slightly shallower than the SH-II. The entrance to the throat is tighter yet it shares the same throat size as the SH-II with a standard backbore.