The Internally Threaded Bananabells is made of titanium. The balls of the Bananabell have a crystal in a acute polish that sparkles wonderfully. The slightly bent bar is externally threaded. The balls can be screwed into the internal thread of our Internally Threaded Bananabells. By the way, all the threads in our jewelry collections are standardized, so you can combine the rings, balls, sticks and attachments with each other ! Like all Basics of the Titan Highline®, the article is sterilisable in the autoclave and because of the skin-friendly nature of the material, it is absolutely safe for allergy sufferers.