Tarnish Resistant 304 Stainless Steel Bead Tips, Calotte Ends, Clamshell Knot Cover, Stainless Steel ColorSize: about 4mm wide, 6mm long, 3.5mm thick, hole: 1mm.Bead Tips, Calotte Ends, Clamshell Knot Cover are used to conceal knots at the ends of beaded strands and to connect the strands to the clasp. Great sizes and secure styles in these versatile, all time favorite components.