Stainless Steel Tunnel With Rubber Stopper Ear Expander Plug Set Surgical grade stainless steel with acrylic stopper. Comes in sizes 12g, 10g, 8g, 6g, 4g, 2g, 0g, 00g, 7/16", 1/2", 9/16", 5/8", 3/4", 13/16", 7/8" and 1". Hollow tunnel or hollow post design. Classic round shape. Great for beginners or enthusiasts in ear expansion.