Native Treasure - 18" Set of 3 Smooth Puka Shell Necklaces - Black, Brown, and Gray - 6mm (1/4") Set of Three (3) Standard 18" Length. MORE Sizes in Our Store! 5mm (3/16") Super Class 'A' Quality Shells Hand-Crafted in Our Tropical Jewelry Shop by our Native Island Artisans Includes Stainless Steel Beading Wire Upgrade, Silver Plated Trim, Sturdy Twist-Barrel Lock 60 Day Free Breakage Replacement 100% Satisfaction Guarantee