This is a professional grade metal banana plug. This single wire connector is used for joining wire to audio equipment. Made from 24k gold plating, FireFold's banana plugs are easy to use and are an excellent way of providing a secure connection for your wire. They are color coded and will connect up to 3.5mm diameter wire. The banana plugs from FireFold come with a Lifetime Warranty, making them the perfect choice for all your audio needs.