AMVIC has four manufacturing sites in the United States and one in Canada. It manufactures units with a higher than normal foam density (1.5 pounds per cubic inch). In form capacity tests, its units withstood pressures of more than 850 pounds per square foot. The units come pre-assembled—no jobsite assembly of the ICF units is required. Units are reversible, including corners. When in place, the blocks lock together. AMVIC reports good concrete flow through the webs. A 1-inch dowel is placed on outside corners for easy attachment of exterior cladding.