THE RING - This particular ring boasts a contemporary flat band, slight comfort fit and a matte finish. The matte finish is extremely durable with a green day color and a green glowing interior. Made with carbon fiber and composite for the glow. RING SIZE- All of our rings can be made from size 4-16 including half sizes. We can make the band width from 4mm-10mm. Please leave us a note in the "Note from Buyer" section of the order to confirm your ring size and band width you would like to receive. PROPRIETARY NASA TECHNOLOGY IN EVERY RING - Having decades of experience with carbon fiber and composites, we invented a unique process for NASA that we use in every Core Carbon Ring made. The process allows for an extremely strong, lightweight, comfortable, and truly unique ring. THE GLOW - We use a Non-toxic strontium aluminate infused in our resin for the glow. Glow times vary depending on charge time and sunlight exposure/UV light exposure. When charged with the included UV light for 5 to 10 seconds, the ring will glow strong for a couple of minutes then the glow will dim for one to four hours. It is necessary to be in a dark or dimly lit space to see the full affect of the glow. The ring can be recharged for 10+ years. Included is a UV mini light to charge your new glow ring anywhere you are! HANDCRAFTED IN THE UNITED STATES - Each ring is professionally and individually handcrafted on the Space Coast of Florida. SATISFACTION GUARANTEE - We want you to be completely satisfied with your new ring. If you are not for any reason, please contact us. We will be happy to exchange until the ring is a perfect fit or refund you for your order.