Mamiya 120 6x7cm Pro S film back for RB67 zinc Unsure what makes this "Tri":

Unsure what makes this "Tri": There's a top compartment (measuring approximately 14x14x24cm) and a bottom compartment (about 15x22x26cm) but I'd assume a third compartment to complete the count

mostly on the collapsible barrel

and any other application which requires the utmost focus precision

The Gossen Luna-Pro is a good quality meter with excellent low light sensitivity and an easy to read dial

manual-diaphragm M42 lens- not even a preset system on this one

Mamiya 120 6x7cm Pro S film back for RB67 zinc Unsure what makes this "Tri":This is a 6x7cm format 120 film back for the Mamiya RB67 series of cameras. This Pro S version is compatible with all RB67 models. In very good cosmetic condition, with light surface wear. Film tested, working well.