Feature:1. Enhanced Sound Quality: The port tube sponge effectively reduces stationary wave caused by speaker vibration, minimizing wind noise and humming, enhancing the listening experience of the mid and low frequencies.2. Improved Bass Response: The air port sponge improves sound by providing better 'bass reflex' effect, enhancing the bass response, suitable for speakers, home speakers, car speakers, portable speakers, and subwoofers.3. Easy Installation: The air vent port tube sponge is easy to install, just insert the sponge into the mouth of the speaker terminal tube and experience improved sound quality.4. Correct Sponge Size: Choose sponge size based on inner diameter of speaker port, with sponge diameter 5mm larger than the port for stable fitting.5. Premium Sponge Material: Made of high strength sponge material, this replacement sponge is sturdy and robust, resisting daily wear and tear, ensuring long lasting use.Specification:Item Type: Speaker Port Tube SpongeSize: Approx. Diameter: 80mm / 3.15in, Height: 80mm / 3.15in (Manual measurement may have error).Package List:5 x Speaker Port Tube SpongeNote:The sponge is produced by stamping process, and slight dimensional errors in the product are normal.