The Singing Machine SMG-901 professional karaoke system helps amateur singers to perform in full synchronization with a prerecorded music video or music. The 5.5" black and white display shows the song lyrics as you sing. This singing karaoke machine has 2 microphone jacks with volume controls. The automatic voice control helps you produce the best sound possible. The echo control lets you adjust the echo volume, echo delay or repeat. It also has balance control and master volume control. The Singing Machine CDG karaoke machine is compatible with CD+G and CD media types.