Galvanized Steel Reducing Washer 2″ to 1″
https://hotfix.nsiindustries.com/product/galvanized-steel-reducing-washer-2-to-1/
The Bridgeport 2″ to 1″ Galvanized Steel Reducing Washer is used in pairs to reduce the size of knockout holes in a box or enclosure. The washer features raised flanges that allow for positive seating in the knockout.