seven inches and a width dimension of approximately forty eight inches a pair of mounting plates 26 is secured adjacent to side edge 28 of the upper panel member 12 in the lowermost portion thereof adjacent to the bottom edge 30 of the upper panel member there are affixed a pair of laterally extending spacer members 32 a 32 b which are spaced apart a predetermined distance so as to form a central opening 34 therebetween the upper panel member 14 is also provided with a centrally located cut out 35 which permits observation of the exterior of the building structure the outer side that is susceptible to attack from the inside the safe side that is non attack susceptible the cut out 35 is contoured in shape to serve as a gun port for extending therethrough and holding therein a barrel of a firearm a transparent fixed or removable shield 37 is suitably designed to cover the cut out 35 and is made of a ballistic material the height and width dimensions of both of the lower and upper panel members 12 and 14 can be made larger or smaller so to accommodate different size window openings in the building structure while the panel members have been illustrated to be rectangular in shape it should be apparent to those skilled in the art that the panel members may be formed of a square oval elliptical or circular shape as well the pair of piano hinges 16 a 16 b are mounted on the respective spacers 23 a.