This sale is for one unused Mamiya RZ67 / RB67 fit 105mm front lens cap, suitable for use with the RB / RZ 75mm shift lens, 500mm f8 lens, APO 500mm f6 lens, and 645 PRO 500mm f5.6 lens.
This push-on cap is in mint condition and probably has never been used. This is an extremely rare item. I can only find one for sale on eBay (in used condition for $54 in the USA).
If you want a few caps (in other sizes), just ask. Plenty of caps in most Mamiya and Bronica sizes in stock.