Plain butterfly labret (ear cartilage piercing) threaded stud. Not suitable for new piercings. Labret studs were originally designed for use in lip piercings. This is a term now also commonly applied to studs used for a variety of ear piercings, from earlobes to conch and upper ear piercings. Our studs are designed to be worn in the ear. They function in the same way as a butterfly back but are 'threaded' and screw-in which makes them very secure.