4" Round Screened Vent - tab style, white - bag of 4 Open Screen vents They fit into the hole

They fit into the hole made by a drill-type hole saw  and are held in place by 4 tabs on the side of the vent

These small round plugs are made of Aluminum

Fits into a 2 inch round hole

They do not have insect screens

They do not have screens

4" Round Screened Vent - tab style, white - bag of 4 Open Screen vents They fit into the hole4" Round White Screened Vent, tab style bag of 4 RWT 100 4" 4PK These round aluminum have louvers and a screen to keep insects out. They are easy to install. They fit into the hole made by a drill type hole saw and are held in place by 4 tabs on the side of the vent. No nails or screws are needed. Note: These are made for thin materials like metal, glass or plastic. They do not work well in wood. The tabs need to be bent over from the rear. Fits into