I actually use my Polaroid MP3, both as a digital copy stand and with the original Polaroid film pack holder. My Polaroid film pack holder is beyond well used. I want to replace my aging and crudely rebuilt Polaroid pack holder with a better one. I am not sure if this holder was used on any other cameras, and this one does seem specific, especially with the dark-slide interlock system. I could also use an OE cable release, as mine is broken. I always read how people don't want these, but I like mine. I use it all the time. Thanks!