["Description:\nbrand new and high quality\nFeature:\nBass radiator, also known as passive speaker, is used to replace the inverted tube, the subwoofer made with the radiator and the traditional back subwoofer.\nLow frequency dive depth and backward , But the sense of speed is significantly faster than the back-type.\nTight box advantage, Get rid of inverted pipe mouth to bring the wind noise.\nAllow you to mass tune the passive radiator to obtain the for ideal tuning frequency and additional without any additional amplifier power or enclosure volume.\nDramatically increase subwoofer efficiency and capability for ultra low frequency reproduction at high decibel levels.\nBass Vibrating Diaphragm only, other accessories demo in the picture is not included!\n\nSpecifications:\nItem Type: Bass Vibrating Diaphragm\nMaterial: Rubber\nSize: 75mm/2.9in, 90mm/3.5in, 92mm/3.6in, 139mm/5.4in(Optional)\nColor: Black\nQuantity: 2 PCS\n\nNote:\nNo retail package.\nTransition: 1cm=10mm=0.39inch\nPlease allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid.\nDue to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!\n\nPackage Includes:\n2 x Bass Vibrating Diaphragm"]