The outside dimensions of the opening are 30 1/2" high (in some places 30 1/4") by 27 1/2" wide (also 27 3/4" in some paces). The upper and lower gap for seating the screen is 3/8" thick. The walls against which the screen can be placed on are roughly 1/2" on left & right, 1/4" at bottom and 3/8" at top. Apparently these are Alcoa brand because "Alcoa" is the lettering on the latches. My best guess is that the windows were purchased as new in 2005.
I am thinking of purchasing kits at Menards but would still need to know decent dimensions / hardware / design that would allow for snugness, ease of removal and theft prevention.
Also, I have two to four American windows to have screens installed on.
