Up for auction is are two pairs of engine compartment vent chambers with vent covers. The vent plastic ,inside the boat, chambers are made by PolyPro and are constructed with two holes to receive two 3" vent hoses on the inside and the plastic vent cover that fits on the outside of the boat. The inside chambers require a hole 15 1/2" x 2" and will protrude into the boat 4". The vent covers are black plastice, made by Attwood and are part # 1423 and are 17 1/2" x 2 3/4" (they have two pre-drilled holes in each end for easy installation). Again, up for auction is 2-vent chambers, and 2-vent covers. All my auctions have no reserve.