Bluetooth Speaker SYS3 BT20 137 240VThe Bluetooth? speaker in the Systainer format ? tool underneath and music on topExcellent sound thanks to four neodymium speakers and two bass reflex systemsBluetooth? 5 with TWS (true wireless stereo) enables users to produce a stereo sound which fills the room by connecting two TOPROCK speakersPower bank function: USB port for charging external devicesIntuitive operation and illuminated buttonsOperation with an integrated battery or power cable