Anatometal's Niobium segment ring is available in all the same colors as titanium, with the addition of Black, and Opalescent. Each ring is hand polished to a mirror finish to ensure the smoothest wearing surface possible. Niobium is a hypoallergenic metal, and slightly easier to bend than Stainless Steel or Titanium.
Segment rings work like captive bead rings, but rather than a bead that comes out of the ring, it's a segment of the ring. The segment portion of the ring has little "nubs" that fit into corresponding holes in the ring ends. Segment = male, ring ends = female. Segment rings are actually more difficult to open than captive bead rings because the ring must be opened a bit wider to allow the nubs to come out of the ring ends. You may want to invest in ring opening pliers to help with the task, especially for larger gauge rings.