BY-W4 is a wireless microphone system that offers broadcast quality & reliable performance with clear, crisp audio. Featuring four channels, it is perfect for multi-person interviews, live performances, live streaming, conferences, panel discussions, or other events. 4-Channel Wireless System, Remarkably Easy-to-Use The BY-W4 features a wireless system that allows for up to four microphones to be used simultaneously, making it perfect for group presentations, conferences, or interviews. Incredible Broadcast-Quality Audio With a high-quality built-in omnidirectional microphone also an impressive sensitivity of -42dB, the BY-W4 delivers much more clear & detailed audio, ensuring that your voice is heard loud & clear.