It belongs to Aegis, the God of the violent seas. Meaning "Helm of Terror/Awe", and "Helm of Aegis". It was believed to protect in battle by making the user appear more fearsome, or to make a stealthy approach invisible. It was also believed that the symbol would take all the negative magic directed at the wearer and send it back 24 fold. The dragon Fáfnir was said to have the Helm of Awe between his eyes/in his possession (depending on translation/interpretation of the sagas).
According to tradition, the Aegishjalmar should be worn over the forehead, perhaps scratched or drawn on the inside of one's helmet. Its purpose is protection and "irresistibility" in battle, One could also draw it on one's forehead with coal, saliva or blood.
The sign may also be viewed as a series of Runes, aka bindrunes. Thus enabling the user to design various types of Aegishjalmar for different purposes. An Aegishjalmar can be designed to enhance different attributes, but the terminations of the branches have to be constructed carefully to let some energy move freely and to keep other forms within the compass of the design.
It should be carved in lead and pressed to one's forehead when expecting an enemy and then one will conquer him. Another source says that the stave is also powerfull against the tyranny of aristokrats, what today would be called misuse of power.
The word aegishjalmar literally means "the covering or helmet of awe and terror". This sigil gives you the power to strike paralyzing fear into the enemy.
It is associated with the mythical power of snakes to paralyze their prey.
Hildigrim
Helmet of Thiðrek
Shield of Nuodung
Weapons
Balmung
sword of Siegfried
Blodgang
sword of Heimir
Dainsleif
sword of Hogni
Made by the dwarf, Dain
Must kill or taste blood when unsheathed before it can be re-sheathed again.
Ekkisax
sword of Ekka
Gram
sword of Hildebrand
Gungnir
the spear of Odin
Made by the four sons of Ivaldi the dwarf.
Returns to user, never misses.
Hrunting
sword of Unferth
Lagulf
sword of Hildebrand
Mimung
sword of Wayland
Mjollnir
Made by the dwarf brothers, Brokk and Eiti
Lightning and thunder, returns to user, never misses, requires magical iron gloves to wield.
Nægling
sword of Beowulf
Naglhring
sword of Grim
Made by the dwarf Alfrek
Refil
the sword of Regin
Ridill and Rotti
Magical swords.
Sword of Freyr
Ornaments
Brísingamen
necklace of Freyja
Made by four dwarfs, known as the Brisings.
Draupner
Odin's Ring of Power
Created by the dwarf brothers, Brokk and Eiti.
The ring could create nine other gold rings
Misceleanous
Gjallahorn
horn of Heimdall
Gleipnir
A magic silk ribbon of binding.
Grídarvöl
staff of Thor
Given by the giantess Grid
Megingjarpar
belt of Thor
Given by the giantess Grid
Strength.
Skidbladnir
ship of Freyr
Made by the four sons of Ivaldi the dwarf.
Collapsible ship, fits in the pocket.