Part Number: 0386-0849 Principle: It uses a float ball to visually confirm the nitrogen is flowing during the brazing of copper tubing in HVAC systems Application: Use with any nitrogen-purging regulator equipped with a 7/16Inch - 20 male flare, provide extremely low flow high precision gas control for nitrogen purging applications, prevent internal oxidization and scale build-up Package Including: 1PC Nitrogen Flow Meter