Description: brand new and high quality Features: 1.Bass radiator, also known as passive speaker, is used to replace the inverted tube, the subwoofer made with the radiator and the traditional back subwoofer, compared to the following advantages, low frequency dive depth and backward , But the sense of speed is significantly faster than the back-type. 2.possession of a certain tight box advantage, but also completely put an outrageous structure of a drawback - that is, inverted pipe mouth to bring the wind noise. So like dive deep, but the speed has a higher demand for friends using the radiation pot made subwoofer is the best choice 3.The new and improved Bass radiator, allows you to mass tune the passive radiator to obtain the for ideal tuning frequency and additional without any additional amplifier power or enclosure volume. 4.The Bass radiator can dramatically increase subwoofer efficiency and capability for ultra low frequency reproduction at high decibel levels. Specifications: Color: Black Medium iron plate :1.0mm thick Diameter:52mm Peripheral rubber: 0.6mm thick,65 degrees Material: Rubber+Iron Quantity:1 Pair Note: No retail package. Transition: 1cm=10mm=0.39inch Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package Include: 1 Pair x Speaker Diaphragm (other accessories demo in the picture is not included.)