I installed 7zip on my Mac using Homebrew... version 22.00 installed smoothly. 7zz shows the following for the -m switch: -m{Parameters} : set compression Method -mmt[N] : set number of CPU threads -mx[N] : set compression level: -mx1 (fastest) ... -mx9 (ultra) Are data and header encryption (-mhe=on) available and working on homebrew? I don't get any errors while using it, I'm just not sure if its working.... and if it is working, why its not showing up as an option. M.