Waterline Designs mosquito nets / bug screens are designed out of a long experience from the country of mosquitoes, Sweden. In Sweden we have a range from small gnats (as the No-see-ums) up to regular sized mosquitoes. We don't have any deceases such as Dengue fever or Zika but we all hate them anyway. The sound of a single mosquito in the cabin at bed time can easily ruin your sleep. Our nets are mounted from the inside of the boat, so no one has to go outside to put them on. Just attach a magnet (a metal plate is attached with double-sided tape on the window) on an open hatch. The screen has a chromed steel frame (foldable) that stretches it out. The screen is tightened against the frame of the hatch by a cord attached to the magnet. Done in a few seconds. After use the mosquito net can easily be folded down to a 1/3 of its size for storage. The screens only need to be bigger than the hatch opening. A hatch with opening