The 5th Chakra is associated with the Throat Center and the thyroid and parathyroid glands. It is ruled by the element of ether. Ether is the condition of space and time that allows something to exist. It is the very beginning of the process of manifestation.
If you think of the sequence of elements ether, air, fire, water, and earth as phases of manifestation, then ether is the most subtle of those five elements. It is the twinkle in the eye of the mother and father. Before they even have the heart connection through the element of air, they have the feelings that begin the process of engagement with each other.
As the 5th Chakra opens, you gain the perception of subtlety. You know how to be alert to the very beginnings of cause and effect. You know how to cultivate the implantation of the bija, the seed. The ultimate seed is the Word, so the 5th Chakra is associated with the power of Word, called vaak sidhi. This power is the power to initiate the manifestation of a physical form or action by simply uttering the words that are the seed of that future manifestation.
One of our greatest powers as humans is to initiate a direction of action. Once we've planted a seed, once we've put it into the soil of maya, it follows the laws of maya. As Newton's first law of motion states, it is very difficult to try to change the course of something once it's already in motion. Vaak siddhi, then, is the power to plant seeds that will fulfill someone's ultimate goal and destiny.
The kind of communication that comes from the 5th Chakra is very blunt. So be it, be it so. It represents the power of projection, but that power comes from the certainty of placing something at the beginning of the cycle of creation and knowing that all the laws of the Universe shall support it.
It is a different kind of certainty than that which comes from the accumulation of personal power in the Third Chakra. The power of the 5th Chakra is having your tongue and the tongue of God be the same.
A very effective kundalini mantra for this chakra is Sat Naam Sat Naam Sat Naam Sat Naam Sat Naam Sat Naam Wahay Guroo. The pulse of the Bij Mantra, Sat Naam, is blended rhythmically and attached to the opening of the etheric Gur Mantra, Wahay Guroo. The 5th Chakra is just such a doorway. Master the Word and master the skill to initiate actions that come from the soul.
Excerpt from the KRI Aquarian Teacher Level 1 manual