Vent is rigid white high impact ABS plastic. Independent base is black plastic w/tube for 3" vent hose. Vent slides onto the base and snaps into place after base is screwed to the deck with 4 mounting screws (not included).
Some boats used a similar but slightly different design from a different manufacturer who has gone out of business. It is no longer available. In the earlier design the hose clamped around the outside of the vent collar. That means that the inside diameter of the collar was less than the legally required 3" ID minimum.
This new vent will work in place of the old version. In this case the 3" ID hose fastens inside of the collar so the smallest inside diameter meets the required 3" minimum.
As a result, the mounting hole in the boat is slightly larger. You will have to enlarge the hole slightly to accept the replacement vent.
• Outside: 5.5" X 6"
• Inside diameter of through deck flange: 3-1/4" (to fit a 3" vent hose)
• Outside diameter is 3.4" (use a 3-1/2" hole saw)
• Outside diameter of the mounting flange is 4.6"