Chains, tennis bracelets, bangles and charm pieces, all made from stainless steel with 18 karat gold bonded to the surface by PVD at 1.8 to 2 microns.
A wrist takes constant contact. Desks, sleeves, car doors, sinks. Plated jewellery wears through at exactly those points, which is why most gold bracelets at this price look tired within months. These do not, because the gold is fused into the steel rather than sitting on it.
Most come with an extender, so one size fits comfortably. Wear one, or stack a fine chain under something heavier.