1. High-Performance 32-Bit Arm Processor, Fully Assembled And Tested, Supports , P-25, D-Star And System Integration 2. Onboard Led Displays Status (Tx, Rx, Ptt, Mode) Rf Power Up To 10mw, Sma Antenna Connector, Including Uhf/Vhf Antenna, Can Be Installed Cleanly On All Current Raspberry Pis, Including Pi Zero 3. The Firmware Is Preloaded And Can Be Easily Upgraded Via Software. 4. Uhf 433 900 Mhz, Vhf 144 220 Mhz Opera Frequency 5. Tx And Rx Have Different Frequencies And Support Uhf+Uhf And Uhf+Vhf Modes. Please select Modem: STM32_HS_GPIO Set TX frequency, RX Frequency It is best to Keep the TX and RX frequencies at least 10M apart. Function: SLOT1, SLOT2 support Note: Different Batches May Have Differences In Product Appearance, Color, And Printed Characters, Which Will Not Affect The Use Colour:As Shown Material:PCB+Metal Package Contents: 1 x Expansion Board Module 2 x Antenna 2 x Pin Header 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.