Sound Quality:  Sony MDR-AS20J[by a long margin][almost tied]Panasonic Slimz RP-HJE350K, JBuds original, iLuv City Lights EP322[not so good] SkullCandy ink'd S2INCB, Ult Ear 100Loudest[bars on Sansa]:  iLuv [3-], ink'd [3], Sony[3+], Panasonic [4-], JBuds [4], Ultimate Ears 100[4+]Recommendation:  JBud originals, and save $ for Sennheiser 300Bs or Klipsh S4sThe Sonys were the only earbuds that sounded close to a home stereo with headphones!  They are super comfortable.  On the down side, they don't seal out noise and the wires seem fragile and will tangle frequently.Coltrane's saxophone on "Moments Notice" was the hardest to reproduce.  The Sonys were excellent, the iLuvs were decent, the JBuds and Ult Ear 100s sounded poor, the rest were terrible.The Panasonics sound would still rate second, well behind the Sonys with all the music.  The Panasonic wires tangle.  The iLuvs sound was close to the Panasonics and the wires were manageable.  The iLuvs would extend playing time because they need the least volume.  But, the buds are large, seemed to want to fall out, and may not be super comfortable.The JBuds were the least expensive and sounded OK, but the bass is weak.  These are very comfortable buds.  Wires were manageable, but had a straight plug.  The Ultimate ears sound was poor.  The wires were so stiff they would pull the buds out.The Skullcandy ink'd were disappointing.  [EZ, SC fans!]  "Eruption" was electric, better than my home stereo headphones.  They are efficient and reproduce deep bass notes you don't even hear with the others.  But, the saxophone on "Moments Notice" was unnatural and the other tracks sound hollow and distant.  The ink'd were new, they may improve with break in.  Setting the Sansa EQ to HipHop helped the horn, but overall still no match for the Sonys or the Panasonics.  The wires are a little too stiff and the plug is straight.Tested these earbuds by pausing mid-song and changing buds on a Sansa Clip Zip.  Compared, by pairs, to determine the subjective quality of each against the others.  Tracks used:  "Take Five," Dave Brubeck;  "Belong," R.E.M.; "Bring Me To Life," Evanescense; "Atomic Dog," George Clinton; "Wild Thing," Tone-LOC; "Eruption," Van Halen; all ripped from personal CDs with Windows Media Player[320kb/s] and "Moments Notice," John Coltrane from Amazon MP3. 

Question: What are the sizes of the lens?
Answer: They are super comfortable