Metric adapters and fittings are sized in millimeters rather than inches. And they design standards comply with European standards such as DIN 2353, ISO 8434-1, etc., so they are widely used in Europe and some other countries.

They have the characteristics of high pressure bearing capacity, reliable sealing, corrosion resistance, etc., and are often used in industrial machinery, machine tools, hydraulic machinery and other fields.

They also come in various types, including straight, elbow, tee, and cross fittings. NJ metric adapters have various sealing types, such as o-ring seal, flat face seal, bonded seal, cone seal, bite type and ect.