<Materials & Specifications> －Dimesions: Length: 1.7 cm, width: 1.7 cm. －Materials: Nickel free Rhodium Plated on brass. <Care Instructions> I recommend you to remove jewelry before going to bed or participating in physical activity. Exposure to certain harsh chemicals or environments will result in compromising the integrity of your jewelry. This includes, but is not limited to the following: perspiration, perfumes, cleaning agents, chlorine, salt water, and silver polish.