2 Sterling Silver crimp end caps. 1.3mm internal diameter.  End hole is 2mm.

Sterling Silver is 92.5% silver, the balance being a mixture of other metals including Copper, Zinc and Tin. The resultant alloy is harder and stronger than the soft pure Silver.

Although some items are stamped as Sterling silver, STS or 925, none are hallmarked since for items of less than 7.78 gr (¼ Troy ounce) this is not required.