Carinthia tropen and army sleeping bag liner quick review and overview in english

The tropen is a 1 season bag from carinthia it can be used as a liner for the defence 4 to make that a 4 season bag rated to minus 40 or so the bag liner is a british army cotton liner purchased form varusteleka and the tropen from tacwrk through amazon.de. Also I am a fairly hot sleeper so I believe with the liner I could use the tropen to the minus 1 0r 2 range which I will try out during the winter