Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.
I measured today, and if anybody's interested, it is 21x20 inches, but just slightly tapered at one end. I cut a piece of screen to that size and sewed some velcro into it, and it works great. Some of our Georgia Gnats still make it through, but it definitely helps.
Notice: The advice given on this site is based upon individual or quoted experience, yours may differ. The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.