Hi, I have little to my Cowon D2, Samsung Wave 2, with the caliber In Ears Ultimate Ears Triple fi. 10 and super fi 5 per EB (stands for bass - boost) tested and found fully fit (I am very fussy when it comes to music what clarity, loudness and bass terms) Leg mobile (output for headphones always low on those things because volume limit) creates FIIO that one finally gets out everything from his headphones + phone (also applies to the original In Ears like me from Samsung Wave 2 who listen to the same right grow up to). As an additive: I'm not deaf, it will not be, but it just sounds like at least one felt LEVEL rich at, no matter what hardware you anstöpselt him. Alone in Great Headphones I would recommend a stronger FIIO (I drangemacht between PMP Cowon D2 and Sennheiser HD 530 II, yes, yes that is certainly already 20 years old) appreciate that then is a matter for the "OHM values" or but the milliwatts mW = "'m not an electrician. The good thing about this FIIO is that you no longer have to turn up so loud the MP3 player (then the Nennklirrfaktor is fast becoming big and even my UE then begin unclean aufzuspielen, but I am picky as I said. To the device itself: Approximately a maximum of 20 grams light (kitchen scale, it did not accurately report), thus barely noticeable when worn (by weight) Li-Io battery integrated holds definitely "a few hours" (depends on product and volume of it) - 2 pieces of plastic clips (ie a reserve) for mounting on the FIIO for mounting eg on clothing - 2 piece 3.5mm jack adapter (an approximately 11 cm long, the other about 85 cm.) - And a USB cable for charging from the PC (I, however, prefer to invite to the socket with a USB adapter for power save-. One more thing .I have put in the work for the small demonstration FIIO times with colleagues and let try (once with iPod touch, the slightly older with normal Sony Neck- listeners, and another with a Sony MP3 and original In Ears. The amazement we saw you on the face (big grin). Conclusion: for little money you get a much better sound - and even volume results that impressed. Strong buy recommendation 5 star of (nothing to complain about) with. PS: Sorry for the long text.