The Mamiya Focusing Screen SA402 Standard Matte for 645 AF supplied with the Mamiya 645 AF camera. It is one of three replaceable focusing screens for the camera. The Checker SD 402 is same as Matte, but with perpendicular grid. The grid pattern is ideal as a compositional aid. Grid intersections also useful as reference points for multiple exposures whereas the Matte SA402 is all matte with Fresnel lens, suited for general-purpose photography. Microprism Type C - for Non-AF 645 Lenses is also same as Matte, but with central microprism spot added. It provides an alternative Rangefinder Spot screen for enhanced focusing precision with the manual focus lenses.