The wavelength of fiber on ground side is 1550nm The interface is defined as: RX/TX/AV/VCC/GND RX is connected to CRSFTX of flight control, and TX is connected to CRSFRX of flight control The AV on ground side is output to AV signal input port of display or VTX, and VCC power supply voltage is 5.5V~26V Power supply: 5.5V-26V: (2S-6S battery) Power consumption: less than or equal to 5W Communication interface: MX-SH1.0mm-5P: CRSF interface/CVBS video port Fiber optic interface: FC: Communication distance: maximum 20KM Note: The product indicator lights from top to bottom are: power light, fiber optic light, video light, data light; GND is ground wire, VCC is power supply, AV is video, TX is TTL signal output, and RX is TTL signal input. Due to different batches, there may be differences in product appearance, color, and printed text, which not affect use. Color: Green Material: PC+Plastic Package Contents: 1 * Ground RX Module Only above package content, other products are not included. Note: Light reflection and different displays may cause color of item in picture a little different from real thing. The measurement allowed error is +/- 1-3cm.