The UDT Badge Gold Mini is. gold plated metal badge usually worn by the family members or friends to show support for the Navy SEALs. It is designed to honor the Underwater Demolition Teams which were an elite special-purpose force established by the United States Navy during World War II. The UDT Badge may be worn on jackets, hats, or bags to display your pride for the military troops who brave the danger of tactical missions to protect and defend the nation and its citizens. Measuring 1.25" (W). .75" (H), this UDT badge will make. wonderful addition to your army memorabilia.