Feature: 1. Reduce Standing Waves: It plays a vital role in minimizing standing waves generated by speaker vibrations. By effectively dampening these waves, the sponge reduces unwanted wind noise and buzzing sounds, contributing to a more enjoyable listening experience. 2. Enhance Bass Reflex Effect: The sponge provides enhanced bass reflex capabilities for speakers, improving the low frequency response across a variety of speaker types. 3. Wide Compatibility: It is versatile and suitable for a wide range of equipment, including modified speakers, home speakers, car speakers, portable speakers, and PA DJ subwoofers. 4. Choose the Right Size: According to the inner diameter of the speaker port tube, choose the diameter of the sponge plug you need. The diameter of the sponge should be slightly larger than the inner diameter of the speaker port tube by 5mm. The larger sponges will be able to be stuck in the speaker port tube in a stable manner. 5. Easy Installation: By easily inserting the sponge with correct diameter into the speaker's port tube, you can enhance sound quality in just moments, making it an effortless upgrade for any sound setup. Specification: Item Type: Speaker Port Tube Sponge Material: Sponge Product Size: Approx. 100x60mm / 3.9x2.4in. Package List: 2 x Speaker Port Tube Sponge Note: Sponge is stamping process production, product size has a slight error is normal.