Hasselblad Magazine 24 220 6x6 Black Film Back [EX+]
This is the 24 exposure 220 film back for Hasselblad 500 series cameras. Note that 220 is no longer widely available but you can still find some expired on eBay. I've also heard of people using the A24 back and a conversion kit to shoot 35mm through a Hasselblad.
It is in excellent condition with light wear and works perfectly. The serial numbers match. The light seals could maybe use replacement.