The term vismod is an abbreviation of the term visually modified, and is used by the elements of the United States Department of Defense to refer to any vehicle, aircraft, or other object that has been altered to simulate equipment used by an enemy for training purposes, often by specialized units referred to as the OpFor or opposing force. It is also sometimes used in filmmaking and television production to simulate real-world military equipment that is required for a scene in a television show or movie but cannot be procured due to financial or other complications. Below are some of the most well-known examples of vismod usage.