brand new and high quality Features: 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. The low frequency dive depth is equivalent to the reverse type. The sense of speed is obviously faster than that of the reverse type, which has the advantage of a certain closed box. Completely eliminates the drawback of the inverted structure - that is, the wind noise brought by the inverted nozzle. Make great effect on enhancing the , booster, convenient debugging. Increase the lower potential of the , the sound more excellent. Vibration Membrane only, other accessories demo in the picture are not included! Specification: Material: Metal+Rubber Type: Accessories Color: As Pictures Shown Dimension(Diameter): 55x44x39cm/ 2.17x1.73x1.54in Quantity: 1 Set Note: 1.No retail package. 2.Please allow 0-1cm error due to manual measurement. plz make sure you do not mind before you bid. 3.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: 2 Pcs x Passive Radiator