Pomona Electronics 7309x Test Plugs and Test Jacks include a variety (73090, 73091, 73092, and 73093) of 4mm banana plugs offering quick wire attachment. Pomona 7309x banana plugs include sheathed, stackable, and retractable sheath plugs. The banana plugs are designed to fit on the end of any 22AWG to 18AWG wire gauge.