After about a year of everyday use, the right earpad of my Audio-Technica ATH-M20xBT (the Bluetooth version of the M20x) started flaking. Strangely, the left one was perfectly fine, but I decided to order two replacements just in case. The description did not specifically mention the Bluetooth version, but I assumed they should still fit (after all, the model number is the same). As soon as I took them out of the bags, I noticed that they were firmer than the old earpads. At first, I thought that the old ones had simply been worn out, but then I realized that the leather-textured polyurethane felt quite a bit thicker on the new pads. Also, unlike the stock pads, they had large (what I assumed to be) ventilation holes on the underside of the foam rings (although, they are nearly imperceptible once the earpads are mounted on the earcups). Overall, they seemed to be much higher quality. The old earpads (and yes, my headphones are genuine) were a lot flimsier. Due to their high compressibility, even my very small ears were touching the inside of the earcups. Thankfully, it does not seem to be the case with these new earpads (at least, for now!). And yes, I changed both of them because I did not want my left ear to suffer with the flimsy old pad. By the way, they were much easier to put on than I had anticipated. I was able to do it by myself in a few minutes — two healthy hands is all you need! It seemed to help when I stretched them out a bit before putting them on. In summary, it is a great, relatively cheap replacement part and a potential improvement for the M20xBT. It would be interesting to know whether they change the acoustics when compared with the softer and unventilated stock earpads.