Known as NO-SEE-UMS screen, this fiberglass screen is a tightly woven 20×20 mesh designed to keep out smaller flying insects. While densely woven, this screen still allows good ventilation and visibility and provides some daytime privacy. Phifer’s fiberglass screening is woven from permanent glass yarn which has been coated with a protective vinyl to ensure lasting beauty, color and flexibility. It is produced under the most exacting conditions to meet extremely rigid specifications. Fiberglass screen is noncombustible and will not rust, corrode or stain.