I am very new to the Hasselblad world having just acquired a Haselblad 500c/m system including a few lenses and a couple of film backs from a retired pro photographer. I’ve been collecting a few bits and pieces such as lens caps, body caps etc. I recently won an auction on ebay for some assorted bits and pieces along these lines which included something that I am at a loss to know what it is. It is a Hasselblad fitting of some sort that attaches to the back of a series V body. It has a large glass screen area. When I set the shutter to Bulb, and set the shutter release button to the T setting so that the lens leaf shutter and auxiliary shutter remain open, I can see the image focussed from the lens projected on to this glass screen at the back. I have attached some photos which should make this all clear. I am quite curious as to what this could be. I suspect it may be a sole part of some sort of system that on its own maybe pretty useless. Nevertheless, if anyone knows, I’d be grateful for any insight.