cotter pins may pass through holes in the bolts 70 to secure the protective panel to the bolts 70 in another embodiment keyhole type openings may be formed in the protective panel 80 and the bolts 70 may include flattened or reduced diameter sections which could be secured in the keyhole openings of the protective panel 80 the corner bracket 50 illustrated in fig5 includes an optional inner layer 57 disposed on the internal surface 55 of the bracket the inner layer 57 may in some embodiments comprise a protective material as described above the inner layer 57 may in some embodiments comprise a resilient material as described above in fig5 an optional resilient material 87 is shown mounted to the inner surface 85 of the protective panel 80 the resilient material 87 may comprise one of the resilient materials described above with respect to the corner bracket 50 in some embodiments the resilient material is only present on areas of the protective panel 80 which overlay portions of the window sash 30 when the protective panel 80 is mounted on the window in use the resilient material 87 may undergo compression as the protective panel 80 is installed on the bolts 70 of the brackets 50 60 forming an air tight or at least substantially air tight seal against the window sash this seal may reduce the likelihood or prevent wind from entering the space between the window glass 20 and the protective panel 80 making it less likely that the protective panel 80 would be ripped off of the window by high winds in some embodiments the resilient material 87 coupled with the protective panel 80.