Model No ZB-ROCKER THUNDER Speaker Channel 1.0 Watt 20 Watt Speaker Connectivity AUX | USB | BT | FM Port / Slot AUX | USB Key Feature BLUETOOTH VERSION: v4.1 SPEAKER OUTPUT: 20W CONNECTIVITY: BLUETOOTH, AUX-IN, MIC-IN, USB FLASH, TF & FM RADIO CHARGING: USB 5V FM RADIO: YES BATTERY CAPACITY: 3.7V 1200mAh MUSIC PLAYBACK TIME: UP to 4hrs* CHARGING TIME: UP TO 3.5 hrs* FREQUENCY RESPONSE: 90Hz - 20kHz FM FREQUENCY RESPONSE: 87.5 - 108mHZ Sensitivity : 60dB OPERATING DISTANCE: 10m Warranty 1 Year from Zoook Service Center