2.75 inch special bass radiator Metal diaphragm for Xtreme bluetooth speaker. Diameter 76mm, speaker opening 66mm, diagonal screw hole 73mm Brief description: The bass radiator is also called passive speaker, which is used to replace the inverted tube. Compared with the traditional inverted subwoofer, the subwoofer made with the radiator has the following advantages. The low-frequency dive depth is equivalent to the inverted type, But the sense of speed is obviously faster than the inverted type, which has the advantage of a certain airtight box, and at the same time completely eliminates one of the disadvantages of the inverted structure-that is, the wind noise caused by the inverted nozzle. So friends who like to dive deep, but have higher requirements for bass speed, use the radiant basin to make subwoofers and Bluetooth speakers. colour: black Material: Plastic Package Contents: 2 x Bass Radiator Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.