The product is made of rhodium plating - the stones are zircon. Sold as a pair. Bar thickness is 1 mm - the stone at the end is 2 mm. Color change is minimized - durability is at a high level. It can be used in the sea, pool and shower. It should be rinsed thoroughly with clear water. It will not darken or fade unless exposed to excessive moisture and chemicals. Since it is a hygiene group product, it is not suitable for exchange or return.