Description: 100 percent brand new and high quality Features: The bass radiator is also called passive speaker. It is used to replace the inverted tube. It has low frequency dive depth, fast sense of speed, low wind noise. It is suitable for all kinds of speakers and other devices. It can transfer the burden of producing bass from small-sized bass unit to larger-sized passive radiator (if the bass unit wants to produce the same loudness sound in the frequency range at the "- 3dB" point, it needs a large amount of air flow propulsion). At this time, the passive radiator can carry out a larger linear vibration (internal and external reciprocating motion of the paper basin). The low frequency response point extends lower. The design uses a smaller size of bass unit, which makes the bass and if response more accurate and better separation. Various colors and sizes to choose from. Easy and convenient to use and operate. Speaker Diaphragm Auxiliary only, other accessories demo in the picture is not included Specifications: Item Type: Speaker Diaphragm Auxiliary Material: RubberandMetal Size: Diameter: 48mm or 1.8in, 56mm or 2.2in, 78mm or 3.07in Color: Black, Red, Blue Quantity: 2 PCS 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 Includes: 2 x Speaker Diaphragm Auxiliary