Gibraltar Industries DVBPSM Vent Block Plug, 5-1/2 in W x 7-3/4 in H Dimensons, Foam

Constructed from foam, lightweight and easy to install or replace seasonally, includes a pair of pre-attached vent plugs, help reduce utility bills, designed to fit snugly within the cavities of Lawrence (Sku # 810-4903), Vent-Air (Sku # 810-4911) and Norwesco (Sku # 117-0182) design block vents (not included).