"Zeiss" Cap (73.5mm inside diameter w/ 3 bayonet fittings) (Contarex ?)

item #735mmzeisscapblackplastic. Condition 9-. I think this cap might be for Zeiss Contarex but I am certainly not sure. The bayonet fittings will just slide over a 72mm filter but this is not how the filter is meant to mount.