RV Designer Provent Dampened Vent White. Plastic construction. Vent can be rotated 360 degree for optimum control in airflow. Outside flange dimensions: 5.5" diameter. Features of RV Designer Provent Dampened Vent Accepts all types of 4" flex duct The damper mechanism can easily be opened and closed and may be completely removed for full flow Grill rotates a full 360 degrees to direct air flow where desired 4" diameter mounting collar; overall 5" diameter 2.75" depth Color: Black Package Contents: RV Designer Provent Dampened Vent RV Designer H820: Provent Dampened Vent White