Since I have apparently no standardized DIN-ears, but still want to wear for aesthetic and comfort reasons, no on-ear headphones I was looking for an alternative to the original earplugs my urBeats by Dr. Dre. what can I say? The difference is so clearly audible that it almost tears of joy had driven into my eyes. The bass deafened and highs and mids are also clearly heard, especially now also at significantly quieter setting of my Galaxy S3, in which I use it. For durability, I can currently say anything yet, but this will supply later in due course. To fit I would say that as a rule of thumb should fit the same size as in the silicone plugs that come with the headset (with me big silicone - Great Comply Foam).
Each halfway audiophile with "problem ears" may I recommend purchasing only fully. For me the sound of a larger jump than of my 17 Euro Philips handsets to the urBeats!
Important note for urBeats owner! Since the size of T-400 for all other beats headphones fit acc. Manufacturer's site (which, incidentally, is exemplary for compatibility checks), urBeats were not listed I ordered this size. Result: You are in the inner diameter a little too big and therefore not hold on to the listeners! This problem can be solved relatively easily with some tape. However what extent that's ok for you I leave you.