Let in natural light and fresh air, or view the evening stars under the skylights! Cosmo Window & Door of L.I. offers a wide variety of skylights, roof windows and sun tunnels for residential and commercial applications. Available in pitched or flat roof, with a variety of flashings, curb types and glazing options. Standard and custom sizes are available with options for manual, electric and solar operation. A wide variety of blinds are also available. Just need a replacement hatch? We can help you with that too.