All 3rd generation Line 6 digital wireless transmitters and receivers are designed to be cross-compatible with each other. For example, the six-channel Relay G30 transmitter will work on channels 1 through 6 of the XD-V75 receiver. The units in question must be on the same RF mode (RF1 or RF2).
3rd generation products include G30, G50, G55, G90 and XD-V 35, XD-V 55, XD-V 70 and XD-V 75.