... 2. Built-in rechargeable lithium battery 3. SD/USB/TF/FM 4. ODM OEM Android Robot mini Speaker Specification: 1, Frequency response ... : 90HZ-20KHZ2, Load power: 3W3, Distortion : ≤0.3%4, Speaker Unit ... battery, when the maximum playing, support for 5 hours. Android Robot mini Speaker