The model shows a general circular shear surface. Sections of circular shear surfaces are used as cambered surfaces. The surface is of fourth order and contains a hyperbolic double curve along which the two mirror-symmetric halves of the surface are joined. The real part of the double curve is bounded by uniplanar pinch points.

The self-shadow boundary of the circular shear surface, which can be seen in the attached drawing, leads to a remarkable accompanying ruled surface, which is also documented in the collection.