S17–S21 (Cervical & Brainstem): Truth & communication micro-chakras (S17 = auditory listening, S18 = speech impulse, S19 = visual truth, S20 = intuition seed, S21 = brainstem/pons switch).
The final tier represents the path to or non-duality. 33 chakras
Above the crown, floating in the pranic sheath: S18 = speech impulse