Here is one of the views of a PRISM that looks like a CD 280 in it's shape and measurements, but has a top CABLE GROOVE. It also looks like a CD 292, but doesn't have the sloped shoulders, and PRISM is not a listed manufacturer of this CD. I am including four pictures of this piece so that you can get a good look at it from all angles. It does have the triple skirts like both of the CD's mentioned above. Am I missing something?? Is this an unlosted piece or have I overlooked the correct CD?? Please help me out with this quandry. Thanks, Peter