Insulated post, external parts insulated Easy installation with screws locking and easy to use Professional made and to ensure the highest quality audio with no distortion Color coded black/dark red for maintaining proper polarity Package Contents: 6xBinding Post (3Black+3Dark Red); bnafes12-month and friendly customer service. Used for demanding speaker enclosure applications where thick walls prohibit the use of conventional cup terminals. Tap the post into place from the outside. Features: Professional made with good performance Stable performance and easy to install Thread Diameter: M8 Dimension: Approx.56*23mm(L*D) Color: Black, Dark Red Package Included: 6pcs x Binding Post