I have tinted glass deer view windows in two blinds.I really like them. I got the fold up configuration. They tell you to make the window hole one inch smaller than the dimension of the glass window for a good fit. I would actually suggest just a little smaller window opening (about another inch smaller) so the felt lining on the inside of the glass has a good contact with the edges of the window opening. IMO
RP, If you buy some 1/4" 3m or equivalent weather stripping, 1" is perfect. I put the weather strip just to the side of the felt and when you use the hasp to close he window, it seals tight!