Rheem External Metal Filter Rack, 21 inch W x 21 inch L x 3-5/8 inch H, Galvanized

Filter Rack, External, Nominal Size: 21 inch W x 21 inch L x 3-5/8 inch H, Metal, Galvanized Finish, Air Opening Inlet Dimensions: 19-1/4inch W x 19-1/2 inch L, Air Opening Outlet Dimensions: 19-1/4inch W x 19-1/2 inch L, Hinged Door, Yes Insulation, For Upflow - Electric, Filter Size: 20 inch x 20 inch