SHIV PANCHAKSHRI YANTRA
It is a very powerful yantra for Shiv Upasana. This yantra contains the powerful Shiv panchakshri mantra "Om Namah Shivaya". Om Namah Shivaya mantra itself is made of beej letters as our scriptures say which includes different letters na, ma, shi, va, ya. This cyclic recitation is meant to invoke power/energy behind each beeja by initiating it like nung, mang, shing etc and then starting the mantra from that beej letter and completing it to rest of the letters in the mool mantra Om Namah Shivay.
Nung namah shivay
Mung mah shivay na
Shing shivay namah
vung vay namah shi
yung ya namah shiva
This makes it one cycle and then it has to be start again with nung namah shivay.
Yantra may be kept in your home / office / altar facing North/ East /North East direction.