For attachment of cameras or guide scope onto a pair of tube rings
The Vixen Tube Ring Accessory Plate is a 7.5" flat plate and has attachment points for installation on top of a telescope by spanning a pair of tube rings (sold separately).
Accessories such as a camera or guide scope can then be attached to the plate with a 1/4-20 thread center bolt. The two mounting holes are separated by 6.3" (160mm). Most of the area between the two mounting holes are covered with a textured, non-slip rubber covering.