be a mounting slot suitable for receiving the shank of a fastener additionally at least one of the second mounting slots may be a mounting slot suitable for receiving the shank of a fastener referring again to fig1 and 2 the sheet 2 is generally a plastic sheet the sheet 2 may be made of any suitable plastic that will provide suitable impact resistance to protect a door or window from windborne debris for example the sheet 2 may be made of any suitable polypropylene plastic for example the sheet 2 may be made from pro fax u00ae sg702 available from montell polyolefins wilmington del alternatively the sheet 2 may be made from any suitable polyethylene additionally the sheet 2 may be made from any suitable high density polyethylene hdpe for purposes of defining and describing the present invention hdpe is to be understood as referring to polyethylenes having a density above about 0 940 g cm 3 for example the sheet 2 may be made from paxon af50 003 blow molding resin paxon aa60 003 blow molding resin and paxon ba50 100 sheet extrusion and blow molding resin all available from exxonmobil chemical houston tex generally suitable plastics include those having a tensile strength at yield as measured by astm test method d638 of less than about 5500 psi more generally suitable plastics include those having a tensile strength at yield of about 3 000 psi to about 4 600 psi additionally suitable plastics include those having a flexural modulus as measured by astm test method d790 of less than about 250 000 psi and more generally suitable plastics include those having a flexural modulus of about 150 000 psi to about 235 000 psi the sheet 2 may be.