6.5 Foam Speaker Enhancer, 4Pcs Self Adhesive Speaker Fast Rings, Universal High Rebound Sponge Bass Blocker Kit for Car Door Speaker Foam Rings

These are probably best value foam rings out there as it’s affordable and closed cell foam.

I was disappointed that my new aftermarket speakers sounded. Shrill and lacking midbass warmth. After research, I learned that speaker baffles may help. After installation, the sound is much more focused. The kick drum is much more present especially the "knock" around the 100HZ-200HZ area. The warm overall sounds fuller and I can hear more music in the noisy traffic than before the install. I'm astonished how a simple foam ring can make the music that much better. Night and day difference :)

Exactly what I was looking for, avent use the adhesive yet, but it’s 3M and other reviews sais it’s good.

Too thick to fit between speakers and door panel and also rear deck. I took too long installing to return now. Waste of money.

I have a jeep so my speakers are in the front not on the doors, I put in aftermarket speakers and they rattled when they got loud just because they weren’t a perfect fit, I put these in and it stopped the rattle and made the sound quality 1000x better. Highly recommend. Easy to install as long as you know how to take smart speakers in your own car. It sticks very well. They are amazing