linsun k8 Sound Wireless Bluetooth Speaker Connection: Bluetooth connection Interface type: USB Battery capacity: 1200HA Frequency range: 60Hz-15KHz. Special Feature:Portable Radio:Yes Interface Type:USB Cabinet Material:Metal Feature:TF CardBluetooth Use:Karaoke PlayerCustomizeComputerHome TheatreStageMobile PhonePortable Audio Player Power supply: built-in lithium-ion battery Channel: 2 Playing time: 6 hours Expand storage: not supported Bluetooth: 2.1 Number of speakers: 2 Distance: 10m Features: voice calls, voice prompts, insert the card, the radio Playback format: MP4