This is a glass tube filled with neon gas and is similar to a section of ordinary neon sign. When held and pointed at the dome of the generator, the current will light the tube a bright orange. Neon is used, as it is the easiest gas to excite into emitting light. There is a large voltage drop across the tube, so the person holding it will not feel anything. A striking display, especially in a darkened room. The end of the tube is fitted with a foam rubber handle.