I searched everywhere foams to replace the original ones because they were flattened with time and headphones hurt the ears. Could not find anything in the usual shops ... Fortunately, the web is there. These foams arise without problem on a PX 100-II headphones and they are 4 pairs per bag (not 3 as shown on the site)! Sent from Korea, they have a little more than ten days to arrive. Qualitatively, it is a little rough as the original, but also a bit thicker. They still remain comfortable and that's the main ... In sound, the audio balance is somewhat changed, but nothing we can not deal with a good equalizer. Five stars without hesitation ...