The oscillatory magnetization of stage 1 and 2 AsF5 intercalated graphite compounds was measured with the de Haas-van Alphen torque method in fields up to 22 T. From the angular dependence of the de Haas-van Alphen frequency and the cyclotron effective mass we conclude that the Fermi surface is ideally cylindrical. The Landau levels are found to be well separated compared with the broadening due to imperfections. Despite this fact the wave form of the oscillations is perfect sinusoidal in contrast to the standard theory.