This stainless steel CRL Vision Window Frame allows the addition of a Vision Window to almost any door. Commonly used in security applications, Vision Windows provide a means of viewing people before allowing access into a secured area. Vision Windows are for interior or exterior use, and are available with your choice of bullet resistant glazing. Manufactured from 11 gauge stainless steel with a brushed #4 finish, Vision Window Frames are fabricated in sizes to fit your specified opening. They can also be custom made with Speak-Thru and Pass-Thru accessories.