This is a commercial copy of the Gemini XII mission patch. Although the early Gemini missions were numbered with Arabic numerals, later flights used Roman numerals.
Gemini XII, launched on November 11, 1966, was the tenth and last piloted flight in America's second human spaceflight program. James Lovell, Jr. and Edwin "Buzz" Aldrin, Jr. were the astronauts. Gemini XII achieved the seventh rendevous with another spacecraft in the program, an unpiloted Agena target vehicle which had been launched the same day. Additionally, Aldrin conducted two extra-vehicular activities.
This replica was made for commercial sale. Mance Clayton donated it to the National Collection in 1982.