Product name is banana plug socket, fit for : 4mm Banana Plug. The banana plug makes the speaker installation a breeze. The plug socket is an open screw type that accepts bare wires, shovel or other banana plugs.Each pair has a red plug and another black plug for polarity identification. The plug body is gold plated to help prevent corrosion and a smooth connection.Super wear-resistant, anti-oxidation and corrosion , can effectively reduce the data loss, to high sensitivity of the signal.It is suitable for speaker, amplifier terminal, microphones, audio equipment, DVD players, game consoles, mixer, etc.Name: Banana plug socket, fit for: 4mm Banana Plug.The length of the thread part: 5mm.The diameter of the thread part is about 57mmDiameter of socket: 11mmWhole length: 147mmColour:Black+redMaterial:ABSPackage Contents:20 * black plug connector20 * red plug connectorOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.