Federal Reserve Bank Notes were an odd hybrid. It was a national currency issued by the Federal Reserve Banks. Unlike ordinary Federal Reserve Notes, they were direct obligations of the issuing bank, not by the U.S. Government. The production of national currency was halted in 1935. Small-size national bank notes have brown seals, serial numbers and are from the 1929 series.
This bill is sold in a deluxe currency protective sleeve.
Federal Reserve Note Brown Seal: 1929 $50.00 Currency