A barbell bent into about a quarter circle, with a threaded or press-fit end on each side; piercers also call it a banana bar or bent bar. It is the standard jewelry for the eyebrow, rook, snug, vertical labret and navel, anywhere a straight bar would poke and a ring would sit out too far. The navel version with a gem fixed on the bottom end is simply a curved barbell with a name of its own: the belly ring.

Two numbers. Gauge is the thickness of the bar: 16G for eyebrow, rook and vertical labret, 14G for navel and snug, 18G for finer ear work. Length is the straight-line distance between the two ends, not along the curve and not counting the balls: 5/16 inch (8mm) for most eyebrows and rooks, 3/8 inch (10mm) for a fuller brow or a navel, 7/16 inch (11mm) for a navel that needs room. Match the numbers on the bar you wear now; both are on every product page, and our size chart is linked below.

Because the curve follows the piercing instead of levering it. A ring in an eyebrow or rook sits out where towels, glasses and pillows catch it, and on a surface piercing like the eyebrow that lever is what makes jewelry migrate. The curved bar sits close to the skin, which is why piercers use it for healing and most people keep wearing it after. Hoops are for the piercing that is done arguing.

For a healed piercing, less than people think; for a fresh or fussy one, yes. Externally threaded bars have the thread on the post and are the affordable everyday standard. Internally threaded bars keep the post smooth and put the thread inside the ball; threadless ends press in and hold by tension. The title says which. Whatever the thread, give both ends a gentle righty-tighty once a week; balls back off with movement.

Most are 316L surgical steel, the everyday standard, with a trace of nickel locked in the alloy that most people never notice; gold-tone, rose-tone and black are PVD finishes over steel, and matte and ombre colors are soft-touch coatings. For skin that reacts, the implant-grade titanium bars are nickel-free, and the solid 14k gold curved barbells are gold all the way through. The title names the metal and the finish.

It is usually what your piercer put in, which tells you the shape is right; the metal and the length are the questions. Fresh piercings start on a slightly longer bar to allow for swelling and downsize once it settles, and piercers favor implant-grade titanium or steel for the starter. Leave that starter in until you are cleared to swap, then this page is where you choose the bar you actually want to look at.