Clear Sign: Red (Positive) and Black (Negative) indicates polarity on binding post, (+) and (-) are clearly marked on the front and the rear to proper wiring Quality Material: Tough, , anti- ABS plastic mounting plate for long service time; Metal contacts for optimal signal transfer Spring Terminal Design for a quick, tight and secure connection. Simply press down the terminals and insert speaker wire for direct contact. Easy Installation: The speaker box terminal cup is usually installed on the back of the speaker shell, which has 4 mounting holes for easy installation. Please check the size before ordering Wide Application: designed for DIY applications, suitable for subwoofer box, small speaker, surrounding box, center box, small bookshelf box, etc, Weight: 0.56548570203 Pounds, Manufacturer: Frewurwer