Niobium rings in Mermaid greens with stainless steel links form a thicker Byzantine weave necklace. Measures approximately 18 1/4"-21" adjustable with stainless steel lobster clasp. Simply fasten the clasp into the desired link at the length you wish. Niobium and stainless steel do not tarnish. Niobium is also as strong as titanium and is a hypoallergenic metal.