Easy installation: The charging valve for R22 and R410A refrigerants is easy to install. Simply connect it to the end of the charging hose to minimize refrigerant loss during maintenance operations. High-quality material: The air conditioning safety valve is made of high-quality brass, which is very strong, corrosion-resistant and durable. Corrosion resistant, durable and long lasting. Perfect Size: Brass flow control valves are available in most common connection sizes from 1/4" to 5/16". Easy to Use: The air conditioner flow control valve is easy to use, with a top-loading knob and swivel for convenient flow adjustment. Regardless of the position of the safety valve, the operation can be easily changed. High practicality: The thickened flow control valve can accurately control the needles of the high and low pressure valves of the air conditioner, which is safe and practical to prevent burns and refrigerant leakage, and can be easily replaced.