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

https://cleaneverycorner.com/is-a-21000-btu-12k9k-dual-zone-mini-split-enough-for-two-rooms/

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