OCC
OCC is best known for the bikes featured on American Chopper where bikes are built around a theme or, increasingly, for specific corporate or celebrity customers. The company has built custom bikes long before beginning the Discovery Channel show. Additionally, OCC launched a limited edition production line of motorcycles in July 2007, priced beginning at $31,000. These bikes include design elements originally developed for bikes featured on the show.
One of OCC's most popular bikes is The Fire Bike, which was designed by Paul Teutul (Paulie) Jr, to commemorate the New York firefighters who lost their lives on 9/11. The bike itself has been modeled after a fire truck, and an actual steel rivet from the World Trade Center has been integrated into the bike itself, mounted atop the bike's gas tank. Paulie is noted as stating that the bike was themed "343", the number of New York firefighters who gave their lives on 9/11.
Source: wikipedia.org