OM Black Obsidian Pendant: 1.1"(28mm) Diameter , Chain: 20"(50cm) Black stainless steel box chain , Protection Amulet: This OM pendant necklace is not only a fashion jewelry, but also be an amulet, which could give the wearer protection since OM is one of six-syllabled Sanskrit mantra , Gems Properties: Obsidian is said to impel us to grow while still lending support, shield you from affecting by malignant energies and also help to keep your thoughts positive , Come with GIFT BOX; 180 days warranty & free replacement, feel free to contact us