This technique is so powerful because it is a combination of four steps.
The first and most important step is the Yoga Mudra. The very
base of Sushumna Kriya Yoga is the Yoga Mudra.The second step
is the Omkara. The third step is taking deep long breaths
and the last step is concentrating between the two eye brows.
If these steps are considered distinctly, Mudra meditation
is first and by using different Mudras and keeping our eyes
closed is called Mudra meditation. By chanting Omkara with
our eyes closed for 15 to 20 minutes is called Omkara meditation.
Likewise by closing our eyes and using any breathing technique
is called breathing meditation and last concentrating between
our eyebrows is called third eye meditation.
Hence, in this Sushumna Kriya Yoga technique all the
four different techniques are combined as one and hence all
of us receive immense energy and progress four times faster
in our lives.