These bungs are perfect for turning bottles and vases into lights. The slot at the top of the thread allows you to use a screwdriver to tighten the bung, expanding it to fill the void where it's placed. The wire can run straight through them or, if using a side entry, out one side. It's important to remember that there are no standard sizes for these, so always measure the opening of the piece you’re working on before selecting the bung.