Self-contained (active) recovery equipment differs from system-dependent (passive) equipment in that it:

Giải thích

Self-contained equipment has its own compressor or pump and can pull refrigerant from any appliance without relying on the unit. System-dependent equipment has no pump and depends on the appliance's own pressure or compressor, so it may be used only on small appliances. Choose active equipment for high- and low-pressure work.