... bluetooth speaker with SD card/USB/FM radio/Aux port/remote control (ADP-028BT) 1. 2.1 super subwoofer with ... bass2. Hi-tech touchable volume control panel ,touchable control of Volume, Previous, Next, Play and Pause ... volume is proper The unit in the process of charging and operating normally will be slightly hotter ,which is ... SD card/USB/FM radio/Aux port/remote control (ADP-028BT)