Why does ventilation matter? Vents protect your home from heat and moisture buildup and keep fresh air moving. Sturdy and well-built, Ply Gem vents are specially engineered to deter insects, birds and other animals. They’re easy to install on all types of siding and come in hundreds of colors and a variety of designer styles. Best of all, Ply Gem vents are constructed of high-performance, long-lasting vinyl for a lifetime of low maintenance.