![Sea-Dog Stainless Steel Butterfly Vent - Center Knob - 4" [331440-1]](http://boatersemporium.com/cdn/shop/products/77417XL_700x700.jpg?v=1574703438)
![Sea-Dog Stainless Steel Butterfly Vent - Center Knob - 4" [331440-1]](http://boatersemporium.com/cdn/shop/products/77417XL_1000x1000.jpg?v=1574703438)
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).