1.Built-in lithium battery 2.CE,ROSH,FCC approved 3.Professional OEM factory 4. ... on MP3, IPOD, PC, CD, notebook computers.11.High capacity lithium-ion battery can be repeated charging.12.Neutral packing13.It contains Chinese ... %4.Signal to noise: > 80 dB5.Speaker impedance: 4 OZU6.Battery specification: 3.7 V / 600 MAH7.Charge voltage: DC5V / 500 ...