The Adi Mantra is popular in the Kundalini style of yoga. The mantra goes: Ong Namo Guroo Dayv Namo. This translates to I bow and have respect for the teacher and wisdom within myself. The vibrations from the Adi Mantra help to open up the pituitary gland where the third eye is located.
The pituitary gland is a small organ, about the size of a pea, that is found at the base of the brain. Regarded as the “master gland” it is vitally important as it produces many hormones that move throughout the body making the Adi Mantra one of the most powerful and potent of the mantras.
This video gives a great example of how the mantra is performed.