.925 Sterling Silver Layered 2 Strand Necklace Tube Clasp Approximately 4.3 mm Wide and 15 mm Long. Closed Rings Around 3.3 mm Outer Diameter, 1.78 mm Inner Diameter and 20.5 Gauge (0.76 mm) Wire Thickness. Clasps Come Attached With 2 Open 5.5 mm Spring Rings. Price Per Piece.