Internally threaded piercing jewellery makes changing your jewellery easy and painless. Whereas a traditional externally threaded bar uses threads (screw ends) on the bar, an internally threaded barbell has its threads on the ball, which then screw into the bar. This means that the end of the bar is smooth and passes cleanly through your piercing. Internally threaded piercing jewellery is perfect for new piercings and easily irritated piercings. If your piercing is particularly difficult or refuses to heal after a long time you could also try Bioplast piercing jewellery, which is flexible and extremely biocompatible.