We just completed our 2nd prototype rhenium ring and this is the style we are going to go with. It is 4 mm wide, 2 mm thick and has D shaped cross section with rounded inner edges for comfort. Similar to our iridium rings though in a smaller font size, they have an inner surface laser etched inscription of "RWMM Re .9999 XXXX" reflecting our brand, a rhenium ring of 99.99% purity, and a 4 digit serial number which for this first ring is 0001. This ring is a US size 11.5 and has already been purchased by a great customer of ours from Singapore. For now we'll take custom orders and will need between 3 and 4 months to complete a ring. If there is enough interest as there has been for our iridium rings, we'll go with a large batch to stock our standard sizes 8 through 12 at half size intervals. Take this opportunity to wear what's rare!