PAIR Black Fixed Ball Surgical Steel Captive Bead Rings Nipple, Ears (c1)

Only $1.70/pair!

ion plated surgical steel, annealed so you can twist to put on/take off.  Ease of use varies, with larger diameters and smaller gauges very easy to twist, ranging down to the 16g 1/4" which are very likely to be too small and too thick to manipulate using only your hands.