The Om Namah Shivaya Bandana is named after a salutation to the Divine. According to Hindu traditions, the human body is made up of five natural elements and these holy letters represent these elements. Shiv Panchakshari Mantra is said to have evolved from the five seeds of aforesaid natural elements.
Om' purifies Bramhatatva and Crown Chakra
Na energizes the Prithvi Tatva (Earth element)
Ma energizes the Jal Tatva (Water factor)
Shi energizes Agni Tatva (Fire element)
Va energizes Vayu Tatva (Air factor) and
Ya energizes Akash Tatva (Sky element).
Plus it's Rad as Fu!