Scream Ball Closure Ring or BCR - 1.6mm (14 gauge)
Captive bead ring nipple piercings | Radiology Case | Radiopaedia.org
Titanium Captive Bead Earring, Ball Closure Ring (BCR) with Gem Ball Crystals - Piercing for Septum, Eyebrow, Nipple, Lip, Nose, Cartilage and More - Quality Tested by Sheffield Assay Office in England
00G Nipple Ring Pair Captive Bead Ring Stretched Large Gauge Piercing 10mm | eBay