14k gold filled 1mm double rope style chain with spring ring clasp.
The price of this item varies according to length.
I choose to sell this style of gold filled chain in my shop because it is delicate and yet very strong with interlinking double rope styling. The chain is a spiraling round rope style so you never have to worry about it twisting like a flat chain will. The tab end is only 3mm wide so any pendant with a bail opening larger than that will fit on it.
Note that my mannequin has a large 16 inch neck so that the chain will fit differently on anyone with a smaller neck. I also sell this in an 18 inch length.