Check the listing for details. FM Transmitter Module 7-108MHz DC 3-5V Audio Radio Wireless Receiver Microphone. Condition: New. Listed at 9.99 USD. Feature: Advanced digital audio signal processing (DSP) and FM phase-locked loop modulation technique (PLL) ensure less sound distortion and more stable performance. LCD display is more intuitive and accurate, and has very low power consumption and tiny noise interference. Built-in 30-class digital volume adjustment can easily complete volume adjustment by pressing buttons. Automatic storing data when the power is out. Automatic switching from multichannel audio inputs. Using quartz crystal for frequency stabilization, and emission frequency will not drift when temperature changes. Support serial port command control. Specification: Output Power: 100mW Frequency Response: 50Hz to 18KHz Emission Frequency: 87.0MHz to 108.0MHz(close campus broadcast), 76.0MHz to 108.0MHz(open campus broadcast) Frequency Adjustment: 0.1MHz each time press button press, 1.0 MHz each time long press(press and hold) button Modulation Mode: Standard FM Channel: LINE/USB (stereo), MIC (single channel) Equivalent Noise: ≥30dB Input Voltage: DC 3V to 5V Current: 35mA Emission Distance: 100 meters(for reference only, tested with 75cm antenna on open ground). Size: 49 x 26.5mm / 1.93 x 1.04" Display Size: 24 x 15mm / 0.94 x 0.59" Suitable for: FM radio, wireless microphone, computer audio emission (connect through USB) Note: 1, Power supply voltage must be DC 3V to 5V. 2, Do NOT touch the back of the module components when it is working, otherwise it will probably not work normally or burn out from a short circuit.