Spiral barbells are those so much curved that they form a twist. This is why sometimes they are called twisters or twisted barbells. They have their ends overlapping but separated to allow the insertion of the jewelry. Usually they are used as an interesting alternative to the ordinary
curved barbells in eyebrow piercings, earlobes and so on. Their size and diameter can vary so as to suit different types of piercings. See also:
industrial piercing jewelry