The Mamyia sreen is not glass but plastic and can be broken after scratching with a sharp knive or cut by a mini circular saw. The original screen of the 2,8 F is a bright plastic screen which is not bad, the Mamiya screen is not better, if you want a better one, take a Beattie Intensreen or a Maxwell. With these you have the choice between different types, plain, with lines, with microprisms, wit split-image rangefinder. If the original screen is in a good order, I'd not spent so much money for a new screen.