Essential for a reason, these basic hoops go with any outfit. They're great on their own or as part of a stack!Sold as a pairMaterials: 18K gold PVD plated stainless steel, stainless steelMeasurements: When you choose mm size it is of the interior diameter of hoop. Also note that hoops (visible part, not the post that goes through your ears) are 2mm thick for sizes 8mm-12mm and 2.5 mm thick for sizes 16mm and up.Care: These are tarnish and waterproof. However, with all items of this material, do your best to avoid contact with chlorine or salt water, cream, lotion, perfumes, etc. Rinse carefully with water and dry if this does happen.Please be aware that with clicker style hoops such as this, sometimes the post that goes through the ear can get bumped slightly, reducing the secure click to close them. Please verify how these earrings will fit prior to wearing them and make sure to adjust the ear post slightly by pushing up or down on it, as needed until you hear a click (meaning that your earrings will stay shut!)