Installing the bug screens in the lewmar opening ports is a real pain, and I am always worried about them fall out and off the boat. I modified the screen using velcro so they mount from inside the port and are easy to install and remove for closing the port. The first photo shows
a velcro tab I glued gunned to the screen. The second photo is of small tabs I used sticky back velcro to the plastic frame. The third photo is of the screen installed and held in place by the velcro tabs.