Used these to refoam a set of Energy drivers. The originals are foam, but are a bit too pricey for these flea market speakers. These have an excellent DIY price point but are solid rubber, like bicycle tube rubber, instead of that rubbery foam - just so you know. They are fairly well pressed out and the first one worked great, but the second one - there was a warble over 1/5th of the inside ring that is glued to the cone. This made the adhesion part a bit tricky, as I had to carefully keep trying to flatten out the ring as the glue dried to keep the ring edge down. The surrounds themselves are perhaps just a bit too thick for an 8" driver - but for the price and for my garage gym, they worked out very well.