This sale is for one brand new Mamiya RZ67 / RB67 fit 77mm front lens cap, suitable for use with all RB67 and RZ67 lenses except a few very large ones like the 75mm shift.
This pinch-type cap is brand new in original sealed packaging. This is (as far as I can tell) exactly the same cap as used by Canon and Nikon – but in this case is unbranded. The best third party cap I have found.
Plenty in stock – but just one listing here. If you want a few caps (or other sizes), just ask.