Builtin Bluetooth and USB Flash Disk audio input for convenient music streaming.Bluetooth 5.0 for easy music streaming, Steady data transmission, no lagging. Use your smart phone to search for Bluetooth i510B,have your phone connected with it for the first time they do the connectoin automatically next time.To from USB Flash Disk,Enjoy lossless HiFi sound To copy music from your computer or smart phone to the USB Flash Disk or SD Card, then plug the USB or SD Card into the USB jack of to play(Remarks: downloaded music format should be: WAV FLAC,APE,MP3, encrypted files can not be played).Plugin and play, Easy to use Favoriate for HiFi Fans.With USB TypeC power supply in, white indicator light turns on, after the Bluetooth connected with your phone,the Blue indicator light turns on, once plugin the USB Flash Disk, the Red indicator light turns on.(The USB flash disk worked first before the Bluetooth Mode Working, While unplug in the USB flash disk, the Bluetooth Mode start working, is alternative between two modes).Product Name:Bluetooth Model No.:i5I0BAudio Input:Bluetooth/USB Flash DiskAudio Output:3.5MMDimension:10x6.2x2.5cmNet Weight:120gColour:As ShownMaterial:aluminium alloyPackage Contents:1 * Hifi DecoderOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/ 13cm.