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

https://mike-wiki.win/index.php/Is_a_21,000_BTU_(12K%2B9K)_Dual-Zone_Mini_Split_Enough_for_Two_Rooms%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 don’t need an EPA Section 608 license