Galvanized Steel Reducing Washer 1-1/4″ to 3/4″
https://hotfix.nsiindustries.com/product/galvanized-steel-reducing-washer-1-1-4-to-3-4/
The Bridgeport 1-1/4″ to 3/4″ 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.