These are double flared 000G guage 7/16 INCH (12MM) tunnels exactly the same style as the ones seen in the picture. THESE BLUE BLING BLING TUNNELS ARE A GREAT ITEM TO WEAR OUT ON A NIGHT ON THE TOWN. The back is held on with by a threaded nut. The material is 316L surgical steel. A PAIR LIKE THIS WOULD GO FOR MORE THAT $100.00 AT ANY STUDIO. THIS AND ALL MY JEWELERY IS NEW AND HAS NEVER BEEN WORN. THE PICTURE DOES NOT DO THIS PIECE JUSTICE.  SHIPPING IN A PADDED MAILER. I ACCEPT PAYPAL. THANKS AND HAPPY BIDDING. 964A