Review on JIFETOR Refrigerant Recharge Conditioning Measuring Tools & Equipment for Air Conditioning Tools & Equipment by Joe Lantz

Plug and play. I can't be wrong Connect one side to the freon bottle, the other side to the car air conditioner low pressure line. Check the pressure against the ambient temperature and open the valve. Any caveman could do it. The extra long hose is a plus as most low pressure lines are hard to reach, more than enough to comfortably charge the system. It works well with freon and stops leaks.