Black obsidian stone single flare plugs with grooves so your "O" ring will stay secure! Color and pattern will be unique due to the nature of the stone. These are handcrafted, smooth and polished and have a full length of about 14mm and a wearable area of about 12mm. These are available in sizes 8G (3mm) - 1/2" (12mm). Sold in pairs (2 pairs).