Whether connecting a clasp to a chain or linking the rings together to create chainmaille jewelry, jump rings are one of the most versatile findings available for jewelry assembly. The gauge, also known as the size of the wire the ring is made of, is choosen according to the durability needs of the design and the overall size of items being linked together. The thicker the wire, the more durable the ring. Measures 7mm. 19.5 gauge.