In order to adjust the fit of headphone headphones to choose a shape that fits perfectly into the ear from the 12 pattern is a headphone of the three sizes of the "silicon ring", the size of four "ear cap" is attached. You can now choose fit well 12 patterns from it by using a combination of parts of two types. Thus, compared to headphones earplug conventional type, fit to the ear has been further improved. The Elecom products like traditional, small ear caps "XS" size comes with S smaller than the size that is nice to women "XS" accessory ear caps from size S. Because it is the inner ear system which adopted high-ear sound insulation system that is hard to turbulence and hair style "ear plugs type", I can put it without minding the disturbance of the hair style. Equipped with basic performance that I did well as a headphone reproduction in terms of performance the sound is easy to hear, it can reproduce the well-balanced sound from a low level to a high level. / Model Specifications: Sound Pressure level output 16 (sensitivity):: 10mW Impedance: maximum input 20Hz ~ 20kHz: band frequency reproduction 9mm: caliber driver Sealed 96dB dynamic plug: 3.5mm3-pole mini plug (L-type) code : 1.2m Dimensions: (height) (width) 15 x 16 x (depth) 20mm Weight: (excluding code) about 4g silicon ring (S M L), ear cap (XS S M L) /