Maurice Franklin Louver-1" Round White Polypropylene Plastic Louver with Insect Screen System (Priced Per Bag of 6). 1" PLW-100
These round plastic vents are easy to install. They fit into the hole made by a drill type hole saw and are held in place by knobs on the side. They are used for ventilating soffits and eaves, insect cages, display cases and spice racks.