4" Round Screened Vent - tab style, black - bag of 4 Rain Barrel Vents These round aluminum vents are

These round aluminum vents are easy to install in wood

mill - bag of 6

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

They do not work well in wood

Vent Cap only

4" Round Screened Vent - tab style, black - bag of 4 Rain Barrel Vents These round aluminum vents are4" Round Black Screened Vent, tab style bag of 4 RBLT 100 4" 4PK These round aluminum vents 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.