These pads are very no nonsense, and do exactly what they are supposed to do. The pads acoustically detach your speakers from their surface, which results in a better overall acoustic response, especially in the lower frequencies.
Because of the double pad design, you basically have three options. A horizontal foam padding, a 4% slope, or an 8% slope. This helps making your speaker set up a perfect triangle for optimal audio reception. They will fit most speakers without any issues. There are probably versions out there that have an even denser foam, but for the purpose they serve, this is just excellent padding. Do recommend.