1, DSP + PLL, the frequency is more stable, the frequency will not change with the environment to produce a frequency drift. 2, without any adjustment to bring the fun of DIY beginners. 3, the frequency can be continuously adjusted within a specified range. 4, with a microphone input and speaker volume can be controlled via digital potentiometer. 5, audio input volume can be adjusted via a digital potentiometer. power can be adjusted continuously (non-linear) between the maximum power of 0.5W to 7W. the power output is very good harmonic suppression network, the output spectrum cleaner frequency and volume settings have power failure protection, you do not need to set the next boot! Suite The main parameters: 1, Input voltage: 12V DC 2, the input current: approximately 1.0A 3, the audio signal: Maximum input Vpp less than 1V. 4, microphone type: cylinder microphone or microphone! 5, power output: 0.5W-7W adjustable! 6, the output impedance: 50Ω 7, the operating frequency: 76M-108MHz 8, frequency step: 0.1MHz 9, distortion: 0.03% to 0.1% Color: As Shown Material: PC Package Contents: 1 x 5W FM stereo PLL transmitter 1 x LCD screen