2 attunements, 1 for each flush. This manual is a continuation from the Abundance Flushes 1 and 2. These flushes can stand on their own (meaning, you do not need to be attuned to levels 1 and 2 to use them), but they are, of course, that much more powerful when taken in sequence after the first two levels. Abundance flush empowerments 3 and 4 provide additional refined energy to work on the subtle bodies. The subtle bodies are the spiritual bodies that underly the physical body and form.
The important thing to understand with these flush energies is simply that they work on the subtle level and at a higher vibration than the first two abundance flushes.