The button measures 9/16'' wide and is in mint condition as pictured. Below here, for reference, is some addtional information:
National Radio Institute
From Wikipedia, the free encyclopedia
The National Radio Institute McGraw Hill Continuing Education Center was a private post secondary correspondence school based in Washington, D.C..
History
The National Radio Institute was founded by James E. Smith, a high school teacher, in Washington, D.C., in 1914. It was purchased by McGraw-Hill in 1968 and renamed NRI Schools. James E. Smith remained as NRI chairman until his death in 1973. McGraw-Hill announced in 1999 that it would phase out NRI Schools, citing ''changes in the marketplace''. They ceased operation on March 31, 2002.