Mighty-Seal® Raintight Steel Reducing Washer 1-1/4″ to 3/4″
https://nsiindustries.com/product/mighty-seal-raintight-steel-reducing-washer-1-1-4-to-3-4/
The Bridgeport 1-1/4″ to 3/4″ Raintight Galvanized Steel Reducing Washer is used in pairs to reduce the size of knockout holes in a box or enclosure in wet locations. Users can maintain NEMA 2, 3, 3R and 4 rating on listed enclosures.