The bracelet's called the aegishjalmur helm of awe

's called the aegishjalmur
The helmet of horror
Bracelet made of natural beads: the central one made of black agate 3*3 cm and beads of 12 mm made of garnet

This is one of the mysterious signs of the Northern peoples, a talisman designed to protect its owner from the negative impact of enemies and detractors, and not part of military ammunition, as can be solved by the name. Some associate it with the treasure of the Nibelungs
The helmet of horror is designed to do the following:

accumulate energy;
increase the concentration;
improving attention;
to improve memory;
increase the ability to navigate the terrain;
to repel aggression, directing it to the attacker