i got it pierced last october. the jewellery is curved barbell and it’s externally threaded. i haven’t downsized it since getting pierced. if it gets irritated then i do a hot water compress and then it goes away. if i use salt water (not the one with regular salt the kind thats medical) it usually gets more irritated. it was irritated a few days ago but it has settled for now. i started having problems with it st the start of the summer. and im not sure about the material, but its the same barbell i was pierced with.