A third jersey, alternative jersey, third kit, third sweater or alternative uniform is a jersey or uniform that a sports team can wear instead of its home outfit or its away outfit during games, often when the colors of two competing teams' other uniforms are too similar to contrast easily. Alternative jerseys are also a lucrative means for professional sports organizations to generate revenue, by sales to fans. Of North American sports leagues, the National Football League generates $1.2 billion annually in jersey sales, with the National Basketball Association second, selling $900 million annually. Another use of the alternative uniform is for identifying with causes, like the Central Coast Mariners wear an alternative pink kit on pink ribbon day.