4PCS 6.5 Inch Speaker Foam Rings, Self-Adhesive Door Baffle Enhancer for Stereo Audio Sound, Universal Gasket Car Accessories Bass Blocker Kit

Very nice quality and foam material is very soft and spongy like memory foam.If you do car audio and I have as a hobbyist for 25 years, you know there is some custom work that will always be needed.I installed on 2 of my rear door speakers and one panel is not fitting back. I will use some scissors to cut the foam about an 1/4" and that will help. Another tip, once you apply the foam ring to the speaker and you have an adapter ring for say a Honda, you can bend the outer edge that hangs past the speaker on to the ring all the way around it, it will create sort of a reverse flare and can actually seal better around the speaker hole.