Professional Design: The unique design of internal threaded guide column at the front, allows for easy alignment of the hole and easy installation on the top. The internal thread design enhances stability and reduces the possibility of titanium perforated earrings falling off. Flat back design ensures a comfortable experience when you sleeping, sporting, or showering. Earrings Stud Size : Studs bar length:6/7/8mm,5A cubic zirconia size:2/3/4mm. Each bar and top CZ can be switched at will, you can adjust different sizes to fit your ear piercings or nose piercings in different positions. Not Only Earrings, But Also Nose Rings: The combination of internal threads and flat design is perfect for earring piercing jewelry, suitable for cartilage earring, nose piercings, tragus, helix, conch, daith, rook, medusa, lip, labret, cartilage earring jewelry. Hypoallergenic and Safety: Our piercing jewelry is made of medical implant grade titanium, nickel and lead free, titanium has excellent biocompatibility and is half the weight of surgical stee. Wonderful Gift: These flat back earrings stud inset charming AAAAA+ CZ design makes the earring more attractive, a fabulous gift for your girlfriend, boyfriend, mother, grandma and any women men, Valentine's Day, Mother's Day, Christmas etc.