... ♦SNR: >85dB.♦Impedance: 4 ohm.♦Power supply: 550MH Lithium battery.♦Charging power supply:USB 5V♦40mm internal magnetic, high- quality ... aluminum and iron boron speaker.♦Built-in rechargeable lithium battery, when the maximum playing, support for 2 hours.♦Colorful LED ... Support TF card, mobile phones, computers and other external sources. Robot Mini sound box with TF,USB,Microjack,LED light