Regarding the Hasselblad 645 mask, I purchased this a while ago from the junk section of Fujiya Camera in Nakano, Tokyo. I never obtained an A16 magazine, so I've never used it. Therefore, I don't know which Hasselblad it fits or how to use it. It consists of two pieces, and I've included photos of it disassembled, so please only bid if you can determine its suitability from the images. Please understand that it may not be compatible with your Hasselblad. Please examine the images carefully. This is a junk item, sold as-is, and returns are not accepted to prevent swapping. Thank you.