This is not a quality rating scale, but an indicator of how much pressure or 'depth' a therapist can bring to your massage...
Level 1: A light pressure, relaxing massage
Level 2: A medium pressure massage with no specific trigger point work
Level 3: A medium to deep pressure massage with trigger point work. This is where we get the "knots" out.
Level 4: A very deep pressure massage with trigger point work.