Lox's patented earring back technology ensures a safe, secure grip for earrings of all styles and sizes. Featuring a stainless steel clip and hypo-allergenic plastic body, the locking design offers a firm hold for small and top heavy earrings. Offering more than just security, the patented mechanism also provides some support, allowing large, heavy earrings to stay in place. Each earring back is 7mm in diameter and 3.4mm in depth, and will fit posts from 0.5mm to 1mm in diameter. Package includes 4.