Shakra

Shakra, in Hindu mythology, is Vishnu's celebrated weapon — a circular plate endowed with reason, inflicting mortal wounds and returning to the god after performing its mission of punishment. The inhabitants of the mountainous sections of Northern India still use a similar weapon, which becomes terrible in their hands. It is a plate of hardened steel, two lines thick in the center and keen-edged about the circumference. It may be thrown a distance of two hundred feet, and will penetrate the most approved armor.