Extruded 4" Deep Block "EX" vent
Extruded 1 1/2" Deep Flange "FL" vent

4" Deep Cast Model "C" vent

4" Deep "EX" with opposed
blade damper
1 1/2" Deep "FL" with exterior
operated damper
4" Deep "C" with exterior
operated damper
1 1/2" Deep "FL" vent with extension and opposed blade damper