Acrylic Rhinestone Cabochons, Flat Back, Faceted, Half Round, BlackSize: about 12mm in diameter, 4.5mm thick; about 1000pcs/bag.Lightweight and decent resin cabochons, great for using with flat earstud components, cufflinks, spot pins, button covers and fold-over bails. Use these cabochons with any flat components on a chain or as a drop design.