With many, many years of experience selling tungsten rings, we guarantee that our formulation of tungsten in combination with finish quality, service, delivery and price is better than just about anybody else selling similar products. This is an Excellent Quality Scratch RESISTANT Tungsten Ring, It's Cobalt Free to avoid allergies and has the Carbides to make them Scratch Resistant. The curvature inside the ring is carefully measured and perfectly polished to provide a true comfort fit. Our sizing is also more accurate than most, but even if you make a mistake in measuring your finger and order the wrong size we will exchange it once free of charge, if you just send it back to us. A word of caution; tungsten material being as hard as it is, is a brittle metal and it can shatter if it falls on hard surfaces such as porcelain tiles, so be careful. But at our prices its much cheaper to replace than buying from vendors with lifetime warrantees.