the FrSky FR-USB3 pcb tool is normally used in conjunction with the FR-SPC (sold separately HERE) - to update the firmware of an X4R X4RSP or of any FrSky Smart Port device including D4R-II and X8R receiver etc

includes

• Includes FR-USB3  FUC3 pcb USB cable  - as per photo
• Includes wires as per photo

Note : Instructions - the update process to update FrSky Firmware on devices such as X4R is found here

How to Update the firmware for FrSKY X4R to CPPM : To avoid any issues - be sure to do your X4R connection sequence exactly as per the MWC Team method below - 

• disconnect your X4R from the Air32 Hero flight controller
• connect the FrSKY FR-USB3 + the SPC sold here (together)  , then plug both the FUC3 & SPC into your PC USB port (X4R is not connected yet)
• Run the PC Win 7 Win10 software called FrSky_update_Sport.exe - download  HOST software for PC here 
• Check that your PC COMMPort (can be any number such as COMM PORT 3 or COMM PORT 6) is correctly selected and enabled
• Click "File" - then Select the appropriate FrSky Firmware File (at your own RISK) - file ends in .frk - DOWNLOADS - downloads from FrSky are HERE (at your own risk) for example the X4R firmware is called X4R-X4RSB_cppm_non-EU_150630.frk
• Now - lastly plug the device such as X4R into the other end of the cable (the white 4 pins side port on the X4R) 
• Click "download" and wait for success - done