The quickest way to safely retrofit an older (automotive) R-12 system to R-134a refrigerant. This special injector contains a proprietary PAG-plus lubricant with additives that mix well with the existing mineral oil in the system.
The very dry lybricant is easily injected into the evacuated system ( 1 complete injector per system). Then charge the system with 80% of its original fill - using R-134a - and done is the retrofit.