With RSSI PWM output (0~3.3V) Parallel two X8R to become a 16 channel receiver. SmartPort enabled, realizing two-way full duplex transmission. More number of channels: 1~8ch from conventional channel outputs, 1~16ch from SBUS port,or combine two X8R to become a 16 channels receiver. All 16 channels requires the FrSky Taranis, or the XJT module bound in D16 mode. For 8 channels in D8 Mode you can use the FrSky Taranis or XJT, DJT, DFT, DHT and DHT-U modules.