Deathly Hallows Necklace
Harry Potter possessed all three Hallows. First, he inherited the Cloak of Invisibility from his father, James. Then, he inherited the Resurrection Stone from Dumbledore, which was inside a snitch. Finally, he won the Elder Wand from Draco Malfoy during the escape from Malfoy Manor.
The Sign of the Deathly Hallows is a triangular mark used as a representation of the Deathly Hallows, three legendary objects that allegedly, if united, would make one the "Master of Death," also known as the "Vanquisher of Death" and the "Conqueror of Death." The current Master of Death is Harry Potter. The sign is actually composed of three separate marks that, united, make up the sign. The Elder Wand is represented by the straight vertical line, the Resurrection Stone by the circle surrounding it, and finally a triangle enclosing them both to represent the Cloak of Invisibility.