Wireless Dynamic Microphone with 2.4G Receiver 10 Channels Anti Interference Bluetooth Wireless Two Microphone System for Singing Wedding Party Speech Item Type: Wireless Microphone Material: ABS, Metal Microphone Battery: AAx4 (Excluded) Receiver Built in Battery: Li Battery 500mah Operating Distance: 30m / 98.4ft Or More Bluetooth Version: V5.3 Bluetooth Transmission Distance: 20m / 65.6ft Or More Impedance: 600 (±15%) Ω (at 1KHz) Frequency Response: 50-15KHz Microphone Pickup Pattern: Unidirectional Polarization Signal To Noise Ratio: >70dB Receiver Battery Life: 8 Hours Or More Receiver Charging Time: 2 Hours