Sea-Dog Stainless Steel Butterfly Vent - Center Knob - 4

Stainless Steel Butterfly Vent - Center Knob - 4" 

Butterfly Vents promote air flow preventing mold, mildew, and associated odors. Features a center knob that allows for easy adjustment of the opening. Corrosion resistant 304 stainless steel construction. Installs with four #6 RH fasteners (not included).