a, hi-fi b, stereo sound c, biodegradable cord d, wood housing e, dia.3.5x3 design plug(gold-plated) Biodegradable Stereo Earphone for mp3 SpecificationPower1mW~10mWPlugΦ 3.5 level 3Frequency20~20000Hz Sensitivity 90~110dB Spk Φ8 6U dynamic permanent magnetic Cable length80~140cm MaterialEarphone cordStarch mixtureEarphone housingSolid wood Ear caps Silicon rubber(small, medium, large) 1, All of ...