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.
Constructed of corrosion-resistant ABS plastic with no sharp edges. For 3″ I.D. ventilation system with 1345 collector box. Install with #8 screws.