SDRD Wireless Karaoke System SD-306 Plus is a portable karaoke system with two wireless microphones. Bluetooth connection to smartphone/tablet. Powerful speakers with a total power of 30W deliver clear and loud speech and music. feature: The function of creating a background soundtrack is to mute the voice of the singer in the song. You can turn on any song, press the vocal mute button and the singer's voice will be muted but the music will remain. Ability to play music from a USB flash drive or microSD memory card. Bluetooth connection to mobile phone/tablet. Adjust the echo effect of the karaoke microphone. Voice change function (female voice, male voice...) This model is perfect for adults and children. It can be used both at home and with you, even outdoors, as it is completely portable and wireless. Up to 7 hours of battery life. Play Music: Connect your smartphone to this karaoke system via bluetooth. Turn on any music on your phone, or ready-made karaoke songs on Youtube - these will play through the built-in speakers of the karaoke system. Specification: Bluetooth parameters: compatible with Bluetooth 4. 2Frequency response: 100Hz-18KHzPower adapter: 5V/2ABattery capacity: 3000MahProduct size: about 340*180*208mmProduct weight: about 3.16KG