Hi guys, Another Whatzit for you. These came in a mixed lot of cameras and accessories, but these are the only things marked Futura. I have no idea what they are, or if they are of any value to anyone. But, I'm sure someone here will know. I thought I had photos of every angle, but I seem to have neglected to take a photo of the back(?) side of the rings, where each one has a square-edged notch 1/2" across in numbered flange. The knurled rings rotate independently of the numbered rings.