Cap of Invisibility

Hades' Helm of Darkness, also called the Cap of Invisibility was an object fashioned by the Cyclopes to aid the Olympians in the Titanomachy. It bestows invisibility upon the user. It was borrowed briefly by Perseus in order to escape Stheno and Euryale, Medusa's two immortal Gorgon sisters. It was also used by Athena to intervene on behalf of Diomedes in the Trojan War.

Description
The Helm of Darkness was made for Hades during the war. It grants who'em ever uses it the power to become completely invisible, even to the Gods themselves.
 * Divine item
 * Indestructible item
 * Divine magic
 * Absolute invisibility
 * Invisibility field projection