It's a black choker. My mother had this set aside as part of her assets, along with gold coins, etc., so she could wear it in an emergency. I am selling it because I have no use for it. Although it is unused, there are some areas that have turned white, so I have listed it as having some scratches. The construction is solid, but I don't know the detailed specifications. It will be delivered as is, so if you would like additional photos, please leave a comment. Please consider purchasing with the understanding that it has been stored at home. Length: Approximately 42.2cm (including the clasp) Diameter: Approximately 3mm Color: Black