This sturdy adjustable ring is made of 1mm (18 gauge) round 14Kt yellow gold filled wire.
An overlapped loop and double coil design allows it to be sized from 5 to 7 US / Canada ring sizes (J 1/2 to O UK / Australia ring sizes).
Inner diameter of ring ranges from 15.7mm to 17.35mm. Wear by itself, or attach charm dangles, beads, or wire wrapped components. Stamped 1/20 14K: