This sale is for a mint condition Mamiya 645 Prism Magnifier FD401 for use with the AE and non-metered Super and Pro prism finders.
This much really hard to find prism magnifier is just about unmarked, and includes the eyecup. Just attach it to the back of your prism (after removing the rubber eyecup on the prism) to give much more powerful focusing, especially with close-up and telephoto, by magnifying the central part of the screen. It can be flipped up or down as required to aid focusing and composition. It gives 2x magnification for focusing, and includes a +5 to -5 adjustable dipoptre. A brilliant accessory for your 645 Super, Pro or ProTL camera.
Please note that this cannot be used with the FK402 AE prism finder.