Adopting NE5532 (Single/Dual) signal amplifying adjustment, imported MOS field effect amplifier, which with extreme smooth sound quality, soft and warm tone, transparent treble. Coupling capacitance adopts WIMA, ELNA nonpolarity capacitance; Filtering capacitance using ELNA electrolytic capacitance. With good sound, not sharp high-frequency, elastic low-frequency, you won't feel tired ears for long time listening. Potentiometer is made in Taiwan, with switch, aluminum alloy button. Including 9V 780mAh rechargeable battery, duration can be up to 10~12 hours, 90mins for being full charged, with LED indicator light in the charger. The battery can be charged and discharged for more than 1200 times. Suitable for computer, TV etc.