... the bass more pure and stronger 5) Embedded type lithium battery, can use USB or power adapter for charge, more convenient ... Signal&noise ratio≥80dBImpedance:4 OHM(Ω)Li-ion Input:3.7V~4.2V+0.05V Lithium battery capacity:600mAhSpeaker Unit:45mmCase Material: ... , Notebook, mobile phone, MP3/MP4, etc..6) External rechargeable Li-ion battery 600MAH7) Can connect to Hi-Fi Speaker Our advantageFast making ...