This is the standard screen for the Canon New F1 / F1N pro SLR cameras.  

This is the 'AE' screen, but it is in a case labeled for the PH screen.

Mint condition.

From Canon:

The 'A' =  Center weighted, Average metering

The 'E' =  New Split / Microprism - Laser-matte / fresnel field with split-image spot in the center and surrounding microprism collar. Provides optimum flexibility and focusing accuracy with any of the three focusing aids. Suitable for general applications. Standard screen with the Canon F-1N

Thanks for looking.