Mamiya RZ67 PROII Film Magazine

Mamiya RZ67 PROII is surely one of the most versatile analog medium format camera ever made. 
It is built to last, and capable of shooting in most medium format frame sizes, you can shoot 6x7 which is the default, 6x6 (square), and 6x4,5.

You can use all the previous backs of the RZ67 series.

I've been using my Mamiya RZ67 ProII with 2 backs from previous versions, and after I find that one of my back(the oldest one) I sent them to get serviced and resealed, and then again I find out that the oldest back is once again light leaking, re-servicing it over and over again is annoying thus I decided to invest in a brand new back.

When I opened the new film-back I found out that internally it is very different and more efficient in use of black foam seal. Below are the photos if the film magazines.

Entire edge parts of the older versions door (top once) is covered with light seal foam, and the newer version has some kind of walling which is plastic. The most important part is the near corner parts by the dark slide, which is again covered by light seal foam but covered by walling in newer version. Having solid parts which are blocking the light is better than having soft light seal which can wear off by time, humidity, temperature and usage.

My opinion and recommendation if you are buying new Mamiya or film magazine for your camera, check the back and make sure you get the latest version.