The RVLINK is a long range relay for your RVOSD6. It is already included in the 525USD set. Range: 20- 40km Sensitivity -110dBm
Includes: RVLINK transmitter RVLINK receiver PCB for RVOSD 2x antenna Male to Male servo cable Requires: RVOSD6 RVLINK Rx module. USB updater to load new firmware into RVOSD ( if you are buying this RVLINK to add to a older RVOSD6) Standard R/C receiver with PPM or SBUS output. 2S-4S battery to power the RVLINK transmitter.