An open band is stamped or cast as a broken circle and then closed by hand, which is a genuinely old method — Roman rings worked this way, and the technique survives because it solves a real problem. Online, a ring that must fit exactly has a high return rate; one that adjusts does not.
We are direct about the material. Most "gold" Pixiu rings at this price are brass-toned alloy over a base metal, and the plating wears at the high points within months, leaving a dull patch. Ours is described as alloy throughout so that you are not surprised. If you want this motif in a metal that keeps its colour, the sterling silver option on this page is the honest answer, and it costs more.
To adjust: open gently by hand, fit, and press closed. Do not use pliers, which will mark the surface.