Looking for the exact same prism diagonal as in the picture. I believe it is a Celestron, not too sure of the model number???
Here is an exact description. It has a plastic body with metal back plate and four screws. The main housing is plastic with two set screws for prism adjustment.
The unique characteristic of this diagonal is the 1.25 inch adapter is just slightly wider than the plastic housing.
If you're willing to part with one let me know. Must be exactly as described.