Dual Variable Frequency. Adopts the SMT Process, where Circuit Board Design is Compact. UHF Band (863-865MHz). An Efficient Battery Energy Design that Allows for Longer Continuous Battery Operation. The Receiver and Transmitter use LCD Screen to Show the Frequency. Dedicated to Large and Small Stages, Dance Halls, Conference Rooms and Family Entertainment. Multiple Noise Control Circuit, Helping for Extrenal Disturbance. Excellent Dynamic Heart-Shaped Cartridge for a Clearer Sound. Open use Distance of More than 50 Meters.