This is an extremely rare item that is no longer in production. It is the shutter and iris assembly for any Mamiya 6 or Mamiya 7 lens. This particular model is for the 65mm lens, the only difference being the length of the flex-circuit. This can be swapped with the one from your faulty shutter, quite easily with a soldering iron. I would recommend that you ask a camera repair technician to do the work.
These shutters have not been manufactured for the past 10 years so if you are serious about keeping your Mamiya 6 or 7 working, you really should consider buying this and keep it in a safe place for future use.
Asking for £99.00 including tracked shipping worldwide.