Pics of Bug Screens, screens were attached to the fridge vents with stainless wire. To the hot water heater I removed the vent and put a screen behind it and the round vent I drilled holes in the panel and attached the screen with stainless screws, nuts, and washers. The furnace vent I just used a Camco 4.5x4.5" vent, I did redue the way it mounts, as the spring way was not to my liking. Hardest part of the job was twisting all those wires to hold the screens in place.