Specification:_x000D_Modulation: FM turns the tiny screw on receiver with your screw driver to use a different frequency if interference is experienced_x000D_Frequency response: 87.5 - 108Hz_x000D_Output impedance: 600 ohms_x000D_Controlsparts on transmitter: ONOFF switch, POWER_x000D_LED indicator, Volume control, 3.5mm mic jack_x000D_Controlsparts on receiver: ONOFF switch, POWER_x000D_LED indicator, antenna wire, 14 diameter audio plug_x000D_Operating voltage: DC 9V for transmitter battery is included_x000D_Operating distance: 30m 98ft_x000D_Lapel Mic wire length: 93cm 3ft_x000D_Headset Mic wire length: 95cm 3.1ft_x000D_Transmitter size: 59.6 x 43.3 x 18mm 2.3 x 1.7 x 0.7in_x000D_How to use:_x000D_1. Open the bottom cover of the Transmitter, and then insert the battery into the Transmitter with the correct polarity and close the bottom cover until the click ends._x000D_2. Insert the Microphone's connector into the socket of the transmitter_x000D_3. Open the battery cover of the Receiver, then insert the AA battery into the Receiver with the correct polarity and close the battery cover_x000D_4. Plug the Receiver into the input socket for microphone of amplifier, then remove the switches of the Transmitter or Receiver to ON position, the indicator lamps of the Transmitter and Receiver light, it means that the two devices is normal and are ready for working._x000D_5. There is a volume button on the Transmitter and you can adjust the volume by this button.Package List:_x000D_1 x Wireless Transmitter_x000D_1 x Headworn Microphone _x000D_1 x Headset Microphone_x000D_1 x Tie clip MIC_x000D_