Features: Ultra high frequency wireless microphone effectively avoid interfering frequency, 300 channels adjustable (frequency: 660~689.90MHz). TFT display shows battery level, channel, RF/AF signal, volume, e-cho, EQ, sensitivity, and high/low power, all these settings are adjustable. Built-in rechargeable lithium battery enables about 3 to 4 hours work time after a fully charge. The transmitter can still get clean signal from up to 50 meters away the receiver in an open area. Comes with a clip for mounting the mic on the bell of the sax, which helps create high-level audio on stage. Suitable for sax, trumpet, etc. Provides wonderful clear sound along with other electronic music. Can be used in church service, saxophone recording, live performance, etc. How to Synchronize the Frequency? 1. Power on the transmitter and receiver at first. 2. Long press the button SET of receiver to unlock, and long press it again, then the signal icon start flickering to transmit. 3. Put the two unit close together to sychronize the frequency. 4. And you can enjoy your stage after succussfully synced.