The ring is a black zinc-plated tungsten carbide ring. The ring inscription which is written in the Black Speech of Mordor is laser marked in the outer and inner bands. The black tungsten ring is available in US size 7, 8, 9, 10. For US sizes 7 to 8, the ring has a 6mm ring band and is 2.3-2.5mm thick. For US sizes 9 to 10, the ring has a 8mm ring band and is 2.3-2.5mm thick.
Tungsten carbide is a heavy metal (unlike titanium which is light-weight). Tungsten carbide approximates gold in weight and density.
Tungsten carbide is four times harder than titanium, five times harder than tool steel and ten times harder than gold or sterling silver. Shaped from extremely high density and temperature resistant materials, tungsten rings are among the most durable in the world. The Mohs hardness scale is an indicator of the scratch resistance of minerals. Diamonds register a 10, the highest. Titanium scores a 6. Gold and Platinum run between 2.5 and 4. Tungsten carbide is between 8 and 9.
A stainless steel necklace chain can be bought separately.
Not sure of your ring size? Check this article.