The classic seam ring in 14k or 18k gold.
14k rings feature a "cup & divot" closure and are made by Jewelry This Way.
18k rings feature a flat seam closure and are made by Anatometal.
Seam rings must be carefully opened and closed to avoid damaging the shape of the ring. It may be easiest to have it inserted by a professional piercer. This makes it a better choice for people who do not need to remove and reinsert their jewelry regularly.