The Vixen Mount Adapter - AVT-1011 by Tele Vue:

This Tele Vue adapter is shaped to fit the Vixen mount dovetail, with additional holes spaced to fit the Tele Vue mount cradles. In addition to fitting both mounts, the adapter attaches to all Tele Vue telescopes and the Coronado PST and SolarMax scopes.

The real beauty is that the adapter can stay attached to the telescope's mount ring for easy, instant switching between Tele Vue and Vixen equatorial and Porta mounts. All the hardware necessary to attach the adapter to the telescopes and the mounts is supplied.

OPT Product Number: TE-AVT-1011