SA818S is a cost-effective integrated professional walkie-talkie module, built-in high-speed microcontroller, high-performance RF transceiver chip and RF power amplifier, and provides a standard serial port to communicate with the module, so that the relevant parameters of the module and the transceiver can be set quickly and easily Function to control. Users only need to connect an audio amplifier, microphone, and speaker to this module to work as a small walkie-talkie. The simplified interface and ultra-small size enable this module to be widely used, and it can also be easily and quickly embedded in various handheld devices to improve the overall performance of the terminal product. UHF frequency band: 400-480MHz transmission and reception frequency Bandwidth 12.5 KHz RSSI signal strength indication Open transmission distance is 4-5 kilometers High receiving sensitivity: -124 dBm High integration and small size 38-level CTCSS analog sub-audio code 166-level positive and negative CDCSS digital sub-audio 8-level squelch 8-level adjustable volume High and low power 1W Wide range operating voltage 3.3-5.5 V Built-in EEPROM, data power-off preservation Using 1ppm TCXO crystal oscillator, stable performance Applications: Small intercom Ignore intercom system Building community security system Outdoor sports products Audio monitoring system Colour:Photo Color Material:PCB+Metal Package Contents: 1 x SA818S Walkie Talkie Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.