Lambro 3-1/4 In. x 10 In. White Plastic Kitchen Wall Vent Cap with Damper Duck Nibs under drive head seat

Nibs under drive head seat fastener perfectly in wood

It includes a lock bolt that is key activated from both inside and outside

For use with rigid ductwork

The XXL Big Green Egg

Key retracts bolt from exterior turn piece operates bolt from interior

Lambro 3-1/4 In. x 10 In. White Plastic Kitchen Wall Vent Cap with Damper Duck Nibs under drive head seatOpening closing damper prevents outside elements from entering the vent. Damper is spring loaded to keep damper closed when not in use. UV inhibitor is used to help prevent the premature fading of vent. For 3 1 4" x 10" duct, with damper. For use with rigid ductwork. Plastic.