This wine stopper is made of dichroic glass and comes on a stainless steel wine stop. The wine stop fits 99 percent of wine bottles and gives a beautiful décor to your open wine bottle. Dichroic glass is the term used to describe two completely different types of glass which undergo a color change in certain lighting conditions. One material is a modern composite non-translucent glass that is produced by stacking layers of glass and micro-layers of metals or oxides which give the glass shifting colors depending on the angle of view.