Red dot window sizes?

[Cuz]

Ok, the search function is failing me this morning. Has anyone compared the window sizes across the wide range of handgun optics currently available?  Interested mostly in the Shield, Holosun, and others. I remember there was a discussion here with a comparison of a whole bunch but I can’t seem to find it now, and don’t remember if it listed window sizes, but there was a good pic of them all lined up. Can anyone point me in the right direction?

 

Thanks.