Saturday's shiny objects
This is a Rolleiflash unit. It attaches to the upper taking lens via a bayonet mount and a tightening knob. I've never used it and I don't even know what flash bulbs it takes.
Now, before you think this is wretched excess, consider that I bought one of these for $90 some time ago. The other one turned up at a garage sale where my mom paid $10 for it! Who could resist? I've carried both at the same time, one loaded with slow, fine-grained film and the other loaded with faster stuff. One problem - I used to put stickers on the backs so I'd know which one had which film. The adhesive tended to migrate, so these days I load only one at a time. Sure, there's an ASA reminder wheel on one of them, but I always forget to use it.