NavList:

David:

This could be "aroundtoit", but us it THE roundtoit that people so often mention. Also, what price glory, as some of the German circular slide rules I have seen offered come with fancy prices. Whether or not prices asked are reasonable, who knows, though I suspect  they are worth whatever people are willing to pay for them, which might be a distance from what is asked. Otherwise, I'm curious regarding the seeming popularity differences between circular and "stick" type slide rules. Of course, slide rules of whatever configuration have long since it seems become historical curiosities, despite the fact that within their limitations, they still work as well as they ever did.