The 2D reduced frames have 6 data extensions (as described as well in the 0th extension):

       1. Reduced 2D file in units of ergs/s/cm^2/Angstrom
       2. Weight frame, maximum is set to zero
       3. Noise frame from pixel to pixel variation, corrected for resampling by a factor of 1.52 [ergs/s/cm^2/Angstrom]
       4. Noise frame from the subtracted sky in ergs/s/cm^2/Angstrom. 
       5. 1D response spectrum, constructed from several Tellurics standards observed at similar airmass as the data. Normalized units
       6. 1D flat response spectrum. Normalized units

    The headers now have all relevant information. See below some important notes:
       * For each mask there is general information such as exposure time, airmass, position angle, date etc.
       * For each object the header now also lists all MAGMA mask design information, such as magnitude, RA, DEC, priority, offset (for raw and reduced frame)
       * From the header you now also know the slit number (bottom slit is no 1) and which bars are included (bottom bar is no 1)
       * The headers also list all included frames and their corresponding seeing, weight, and drift. The drift is corrected for the dithers, assuming a pixel scale of 0.1799 in the spatial direction. Note that the spatial direction in the raw frames is not exactly the same as the vertical direction, but along the skylines. 
       * For each mask a scaling factor is given in the header. This is the conversion factor from cts/s to ergs/s/cm^2/Angstrom, as derived from the slit star.
       * Please note that the flux units in 2D spectra do not take into account the object-dependent slit-losses, which have been applied toeach 1D galaxy spectrum. The flux scale in the 2D spectra assumes that all galaxies have the same profile as that of the slit star, which is not correct.