This is a bit more detailed on the previous list I posted......
No. 1 Matte – Entirely matted with Fresnel lens
No. 2 Check – Entirely matted with Fresnel lens and sectional grid markings
No. 3 Rangefinder spot - Entirely matted with Fresnel lens and split prism at center
No. 4 Microprism – Entirely matted with Fresnel lens and micro prism at center
No. 5 Cross-hair – Entirely matted Center small circular portion is transparent with cross hairs marker (useful for high magnification or telephoto, using parallax focusing)
No. 6 Rangefinder spot - 45 deg/microprism