using UHF band, PLL frequency synthesizer technology, stable and reliable UHF780-789MHz band, preset six channels to choose from low-power design, the receiver two alkaline batteries can work more than 24 hours A transmitter within range can be equipped with multiple receivers dynamic expansion of the circuit, high composite jamming circuit can be used simultaneously more than four sets of non-interfering transmitters, receivers are used LCD frequency, channel, battery charge information The use of remote transmitter, distance up to 100 meters Range: For wireless tour guide, simultaneous interpretation and audio-visual and other occasions Carrier frequency: 780-789MHZ Frequency Response: 30Hz - 15KHz Channel: 6 Transmit Power: 10dBm Receiver sensitivity: S / N: 12dB 3uV : 50dB Transmission distance: 100 meters Colour:Black Material:Plastic + Metal Package Contents: 1 x Receiver(2xAA batteries are not included, you need to prepare them yourself) 1 x Transmitter(2xAA batteries are not included, you need to prepare them yourself) 1 x Wearing microphone 1 x Earphone 1 x 3.5mm plug adapter cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.