She's cute, she's versatile, she's out of the world! Similar to our original Lunar Phase Flat Back Stud, this version is quite a bit smaller and it features an opal, rather than a clear zirconia. This listing is for a single ASTM F136 implant grade titanium push-pin flat back stud. Sold individually.Measurements: Post measures at 1/4 inch (6mm) length, with a 4mm disc on back. 18 GA (1mm). Flower is approx. 6mm in diameter. Refer to listing images to get an idea of the size of the stud on-ear. Check your own ear measurement before ordering. Colors available: 18K PVD Gold Plated Titanium, Titanium, Synthetic Opal Care: These are tarnish-proof and waterproof. With all items of this material, if you come into contact with chlorine or salt water, cream, lotion, perfumes, etc. Rinse in water and dry if this does happen. When not wearing, store in a dry, cool place.