Attwood hull-mounted vents are designed to install by fastening as a complete unit from either inside or outside the hull. Ventilation hose (not included) twists into the bottom of the box to form a raised water barrier. Plastic vents are corrosion-resistant, will not discolor. All collector boxes and vents are designed for intake or exhaust and meet ABYC H-2 cross sectional area requirements. For use with plastic louvered vent, with two 3" I.D. wire-supported ventilation hoses. Box fastens to vent with screws or pop rivets, then vent fastens to the deck. > For two 3" I.D. hose > Hole Size: 2-7/16" x 16-1/4" > Depth: 4" > For use with Attwood Vents 1495 line (BC-3718)
