Top selling Wedding Band Ring 4mm for women. This beautiful black and blue tone tungsten ring is 4MM in width. Matte finish top with a high polish grooved center. If you are looking for a ring that is scratch proof and forever keep its shine, than our Tungsten Carbide rings are for you. Tungsten Carbide is ranked second hardest next to diamond on the Mohs scale, diamond being a 10 followed by Tungsten Carbide as 9. Hypoallergenic. Our rings will not cause skin irritations or turn your fingers green. Due to the Hardness of Tungsten, these rings can be laser engraved, but not hand engraved. They CANNOT be stretched. Women's Tungsten Wedding Bands - Black and Blue. (Good news! Matching couples rings in width sizes 2mm, 4mm, 6mm, 8mm, etc. may be available for this style. Please check other product listings)