Features: 【High-Efficiency Wireless Transmission】Features an radio transmitter module utilising the latest microchiped technology, delivering superior frequency stability compared to conventional capacitive three-point oscillators. 【Simple 】The module employs mount devices (SMDs), requiring users to solder the power supply and antenna themselves, catering to enthusiasts' hands-on requirements. 【Multi-Scenario Applications】High-sensitivity microphone type suits wireless recording, remote monitoring, and maternal-infant care scenarios. 【Energy-Efficient Long Battery service】Operating current is merely 9mA (tested at 3V), featuring low power consumption suitable for extended continuous use. 【Flexible Frequency Adjustment】Frequency can be easily adjusted using a small screwdriver via the trimming capacitor on the circuit board, adapting to the reception requirements of different devices . Specifications: Overall dimensions: 20x10mm/0.79x0.39in Working voltages: DC2V-12V Working current: 9mA Launch distance: 100 meters in opened space (3v voltages test) Working frequency: 85MHz-115MHz Output impedance: 50ohms Default factory frequency ranges between 99.0-100.9MHz Working time: The working time of the module is decided by the battery capacity. Package Includes: 1PC radio transmitter module note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.