Conventional ZnS, clear ZnS, ZnSe, and ZnS/ZnSe sandwich materials along with 8 to 12 micrometers anti-reflection (AR) coatings have been used as windows for forward looking infrared (FLIR) thermal imaging electro-optical sensors (such as those incorporated on PAVE TACK, F-18, and LANTIRN pods). Conventional ZnS also has been used as dome material for IR Maverick missiles and other missile applications. All of these systems have separate windows/systems for target designation, rangefinding, and low light level television (LLLTV) applications. New generation system require that a single window provide multispectral capabilities to perform various functions. A graded index AR coating developed at Hughes Danbury Optical Systems (HDOS) provides the multispectral capabilities and is highly durable for subsonic aircraft and missile applications. The spectral performance, durability, rain- erosion, and some sand and dust data of such a coating are presented in this paper. The data is also presented for this coating in conjunction with grids for EMI attenuation. The transmission of the coating as a function angle of incidence is also presented.