These files are for FoxTelem, the AMSAT software for decoding and displaying Fox-1 series CubeSat telemetry.

To use FoxTelem with the CubeSat Simulator, you will need to download the 1.09 version:

https://www.g0kla.com/foxtelem/downloads/test/

Next, download the .MASTER files in this directory and put them in the FoxTelem spacecraft folder.

Run FoxTelem, then go under Spacecraft/Add and select the .MASTER files to add the CubeSat Simulator to FoxTelem.