Product DescriptionAudio Frequency: 40-20KHz Dynamic Range: 95dB System Distortion: 0.5% Signal-to-Noise Ratio: Operating Range: 30M Frequency Channels: 8 channelsCommunication: Wireless Distance: over 30MFrequency: UHFMaterial: MetalModel Number: AK-100Set Type: Transmitter Sets Style: Handheld MicrophoneTransducer: Dynamic Microphone Use: Karaoke MicrophoneTransmitter:Frequency Stability: + - 0.005%RF Output Power: 30mWSpurious Rejection: 40dBPower Supply: 2 * 1.5V AA battery (heandheld microphone), 450mA Li-batter for receive 1) LCD Screen: Display: Frequency, Battery power, Signal, etc. 2) Power Switch: ON / OFF 3) Frequency button: Press-to-change frequency of handheld microphone. Receiver frequency will change automatically. 4) Battery: 2 pcs AA battery supply power.Receiver: Li-battery: 450mA (4-6 hours) Low power light USB interface RF / AF light power switch