The F.L.A.G. Mobile Unit is a semi-trailer truck owned by the Foundation for Law and Government, which functions as a mobile garage for K.I.T.T. and a mobile Headquarters for Devon Miles to relay information to Michael when Michael's and K.I.T.T.'s missions bring them far enough away from F.L.A.G.'s standard HQ. The Mobile Unit is referred to as just "The Semi" on many occasions, but has also been called "The Rook," "Mobile Office" & "Mobile Base." The Mobile Unit was usually parked or driving around somewhere near Michael's & K.I.T.T.'s location.