Duo-Corp. manufactures hopper and slider style vinyl basement windows and egress windows for new construction and replacement applications for both concrete block and poured concrete foundations. Our vinyl utility and barn sash windows are perfect compliments to our family of quality basement and egress products and include features that are ideal for garage, shed, barn or utility building packages. Our Place-N-Pour (PNP) automactic foundation vent completes our poured foundation product offerings.