Thinking about a DIY mini split? These systems come with pre-charged R-454B...

https://fast-wiki.win/index.php/Why_Do_Traditional_Mini_Splits_Need_a_Vacuum_Pulled_to_500_Microns%3F

Thinking about a DIY mini split? These systems come with pre-charged R-454B quick-connect linesets, so you skip the vacuum pump and avoid needing an EPA Section 608 license