Cardioid Pattern: Upgraded high-quality cardioid microphone with excellent feedback suppression. Extensive Use: Stable signal, 200ft operating range (line of sight), suitable for indoor and outdoor activities, such as home karaoke, church, wedding, conference and small stage performance. Quick Setup: Just turn on the system, then the receiver will sync the frequency with the transmitter automatically. 15 adjustable channels to get rid of radio interference, up to 15 sets can be used simultaneously. Rechargeable Battery: The rechargeable and portable receiver only needs to charge for about 2-3 hours and can be used for 6-8 hours. The system features rugged metal construction for dependable performance and long life.