9x6mm TierraCast® silver plated Celtic knot necklace bails. Silver plate is a thin surface layer of actual silver. Necklace bails make adding a jewelry focal to your cord easy. TierraCast uses "Britannia" casting alloy for cast pewter components. Fits cord and chain up to 2.5mm in diameter. Do not open – slide bail over the end of chain or cord and use a jump ring to attach pendant.