[Utah-astronomy] Off-axis Aperture mask

Anyone used an off-axis aperture mask for double stars? Here is a quote from CN forums. I'm thinking a 6 inch off-axis mask would be perfect to try some good doubles. Debbie "As Pete alluded to earlier, the smaller apertures can offer more pleasing views of colorful doubles--I saw this first hand the other night with the 6 inch mask in place--Izar, Cor Caroli, Rasalgethi and many others came alive! I can see why folks love their refractors. Interestingly, on this same night of quite poor seeing, Antares B showed better as a disk separated from the primary when using the 6 inch off-axis mask versus unmasked to the full 15 inches. So, there exists practical utility with its use as well."