4" Round Open Screen Vent, mill - bag of 4 Stainless Steel Vents or PVC pipe

or PVC pipe

These small round plugs are made of Aluminum

822  si nfa (square inches of net free ventilation area)

The twist-locking vent cap installs quickly and easily with standard PVC pipe cement

4" Round Open Screen Vent, mill - bag of 4 Stainless Steel Vents or PVC pipe4" Round Mill Open Screen Vent bag of 4 RS 100 4" 4PK These round aluminum vents have a screen to keep insects out and are easy to install in wood. Not made for glass, metal or PVC pipe. They fit into the hole made by a drill type hole saw and are held in place by knobs on the side of the vent. No nails or screws are needed. Fits into a 4 inch round hole. 7. 380 si nfa (square inches of net free ventilation area). Bag of 4 vents. Made in the USA.