A substitute for vacuum pump
Built-in pressure gauge and vacuum gauge
prevent compressor from spraying oil

2-In-1 Vacuum & Inflation Pump

A substitute for vacuum pump. 
No need to move a hulking Nitrogen Tank to test leakage by high pressure.  
No need to disassemble all components of main cabinet during repairing.  
Leak detecting commercial air conditioning or automotive air conditioning system by air inflation.
Built-in pressure gauge and vacuum gauge, assists user for proper readings and operation.
Built-in special device to prevent compressor from spraying oil.
Built-in device for drying & filtering and oil-water separator