All aluminum construction. Includes 8 in x 8 in perma-coated aluminum screen extended to the edges of the cap. Large nailing flange. Rolled flange on vent stack to prevent weather infiltration. A 600S with a taller throat for use on a shake roofs is available. 60 sq-in of net-free ventilating area. 16-5/8 in x 18-7/8 in x 4 in overall size.
