The Sentinel MF debuted in Spring of 1998 as a limited edition specialty disc. But players started to fall in love with it. So in Spring of 2000, Millennium decided to make it a permanent part of their line. The Sentinel MF is unique among midrange discs. Its rare combination of speed and fade make it perfect for four situations: low ceiling approaches, skip/fade approaches, upwind approaches, and 'reverse S' approaches. It might be a little too much for newer players to handle, but better players will always want to keep the Sentinel around.