Balor's Magical Eye - Nanatsu no taizai

If you are following the anime/manga nanatsu no taizai you will recognize this object. It belongs to hawk a talking pig with "30"00 of power level

Merlin created the Magical Eye with resemblance to Balor's ability of seeing through his enemies and gave it to Hawk as a gift to wear as his new tag. Balor's Magical Eye is used by Hawk to give an accurate measurement of a person's overall "power level". This measurement is further divided among the person's magical power, strength and spirit.