Welcome to our store！</br> 1、The user needs to configure an external audio system, K8 microphone supports multiple input connectors including USB audio input/HD Multimedia Interface input/optical input/3.5mm audio. 2、The volume of the microphone and background song can be adjusted individually through the knob on the back. 3、A professional wireless microphone system with 2 microphones,enjoy music with your friends provide a quality customer experience. 4、With long transmission range approx 65.6in in open space, ensuring that can simultaneously without worrying about interferences. 5、The microphone system is easy to use with multiple systems and is the perfect microphone system for any professional or entertainment activities. <div class="wang-edit-text"><p class="wang-edit-text"> Item Type: Karaoke Box Material: Plastic + Metal Microphone Batteries: 2 x AA Batteries Per Microphone (Not Included) Voltage: 100-240V Frequency: 750MHz-769MHz Effective Distance: &gt; Approx. 65.6in Frequency Response: 50Hz-17KHz Signal To Noise Ratio: &gt; 100dB Distortion: &lt;0.5% <style> .wang-edit-text{ font-family:'Arial' !important; } .wang-edit-text table { border-top: 1px solid #000; border-left: 1px solid #000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid #000; border-right: 1px solid #000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }</style></div> 1 x K8 Home Wireless Karaoke Box 2 x Wireless Microphone (not Including 1.5V AA x 2 Battery) 1 x DC USB Cable 1 x&nbsp;Power Adapter 1 x 3.5 MM Audio Cable 1 x 3.5MM to 2RCA&nbsp;Jack Audio Cable 1 x Manual Satisfaction - Our customers are our top priority. If you find any product problems after receiving the goods, such as damage and incorrect quantity of goods, please contact the seller immediately. We try our best to provide you with satisfactoryaftersalesservice</br>