Description: brand new and high quality Features: Made of high-quality material, durable, firm and stable for us to use. It is mainly used to strengthen the . The enhancer is convenient for debugging. A suitable diaphragm unit is pasted at the back of each speaker, which can increase the lower potential of the and make the timbre more excellent. The diaphragm is suitable for the use of airtight box to enhance the . Multimedia and small size HIFI box use, the effect is improved. The diaphragm is used in a sealed box and cannot be used in a box with air convection. By installing this diaphragm, the cabinet functions as a semi-closed box. Attention: This is not speaker. It is for Bass radiator. Bass Vibration Membrane only, other accessories demo in the picture is not included! Specifications: Item Type: Bass Vibration Membrane Material: sponge+paper cone Size: (Optional) Outer diameter: 5 inch: 127mm/5in, 6.5 inch: 153mm/6.02in, 8 inch: 196mm/7.7in Color: Black 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 Bass Vibration Membrane