Size: about 17MM Material: Alloy ✦Maintenance Tips✦ 1. Avoid Chemicals. Please take it away from cleaning products, perfumes, body moisturizer, ect. It can take off the finish and change color 2. Avoid contact with water, no baths, pools, sea water, etc. If it gets wet that can leave dark water spots which are difficult to remove 3. Please don't wear it when sleeping. To keep your gorgeous jewelry looking like new, take it off at the end of the day and give it a quick wipe down with a microfiber cloth 4. Avoid violent collision. It is easy to deform your jewelry 5. Take it off when you sweating a lot, avoid prolonged wear. It can cause erosion.