316L Surgical Steel hollow single-flare tunnels, easy to insert. Black rubber o-ring included. All plugs measure 10mm (3/8 inch) in length, front to back Perfect basic tunnel plugs. Available in pairs by gauge size, and also in 8 piece (4-pairs) "Stretching Packs," grouped by incremental sets of 4 gauge sizes Forbidden Body Jewelry tunnels Forbidden Body Jewelry is pleased to be your go-to resource for all of your body piercing needs. We are always expanding our diverse collection with the newest styles and trends, so you can continue finding new ways to express your individuality through the art of body jewelry. Whether you are looking for a piece that is simple and understated, eye-catching and pretty, bold and sexy, or somewhere in between, we will help you find the piece that is uniquely you. You can reach out to our Customer Happiness Team at any time with questions, concerns and inquiries - we are passionate about helping you LOVE your piercings!