The Thirty-cent Prexie
Second step registered airmail
Twenty-five cents was the second step ($5.01 - $50) registry fee from March 26, 1944 until January 1, 1949. Airmail postage was five cents per ounce from October 1, 1946 to January 1, 1949.
This cover was mailed in March of 1947 from Adak Island, Alaska to Ketchikan. Since it was registered, it apparently had to be processed in Seattle. The envelope does not look as if it had held double weight, but that is another possibility: minimum registration for twenty cents and double the five cent airmail postage.