2 x 400 frequency on each channels, up to 20 sets can be used at same time True diversity operation for increased range/reliability, reducing dropouts. Automatic frequency scanning to find and set the most interference-free channel in the area Automatic transmitter setup, the channel of the transmitter and receiver can easily synchronize Range: Up to 400 feet (120 meters ) Frequency: 550 Mhz - 590 Mhz (Programable)