1. Forty 9 accessories: This is a small shortwave radio transmitter designed for the Forty 9 Series 3W. With performance and strength, it is an choice for DIY enthusiasts. The included circuit diagram provides installation support. 2. performance: The output power is increased to 3W, enhancing longdistance communication capabilities and improving the comfort of the Forty 9. When the vibration frequency of the kit is firmly set at 7.023 MHz, the receiving frequency ranges from 7.023 to 7.026 MHz. 3. : The addition of an audio monitoring circuit allows the headset to pick up Morse code signals. When using the transmitter with an audio sine wave generator, the effect is significantly better than the typical rectangular wave generator. 4. Uses: This is a compact and simple 40meter band micropower telegraph transceiver. The kit can be easily mounted on a standard aluminum board measuring 65 mm x 35 mm x 100 mm. Note: The case is not included.