Features: brand new and high qualityOOTDTY  It is made of high quality material, durable and practical to use . Upgraded wavy design, better sound insulation effect. Our car speaker foam rings preveant sound quality diffusion, absorb car door echo, enhance horn sound effect and enhance sound effect. Easy and quick installation with Self-adhesive. When fast rings are properly installed, the speaker will "float" in the door so that it can vibrate perfectly.The front fast ring will greatly enhance the mid-bass to get the qualitative leap.Specification: Material:SpongeOuter Diameter:Approx.20cm/7.87inInner Diameter:Approx.15cm/5.91inThickness:Approx.2.5cm/0.98inPackage Includes: 4x Car Speaker Foamnote: Please allow 1mm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item.