Made to mount our 80 mm Stellarvue finder scopes to the Feather Touch 2.5” and 3" focusers. The shoe mounts to these specific focusers to any flat surface or to a tube that is 4” or greater in diameter. These WILL NOT mount to a 2 and 3.5" Feather Touch focuser. When installing the shoe on the Feather Touch focuser obtain 8-32 screws of the proper length. Please be aware if the screws are too long they will scratch the focuser drawtube. So take the shoe with you to make sure the screws are not too long. The shoe dimensions are shown above.