1> FF&FR Stainless Steel Double Ferrule 
Features: Double ferrules offer a wide range of compatible media, excellent corrosion resistance, and superior sealing performance. They are suitable for both vacuum and high-pressure applications, with a working temperature range of –196°C to +350°C. The double ferrule assembly comprises a front ferrule (FF) and a rear ferrule (FR), both manufactured from 316L stainless steel, with the rear ferrule featuring surface hardening treatment. Metric‑size ferrules are paired with UWM‑series nuts, while imperial‑size ferrules are matched with FN‑series nuts; installation instructions can be found in the technical documentation. installation instructions can be found in the technical documentation. 
Model with paired connector (FPM): For metric fittings, add “D-” to the ordering number, for example: D-GV-S16-SL.

II> SR Stainless Steel Single Ferrule 
Features: SR stainless steel single ferrule has high pressure rating, applicable to non-corrosive media like oil and Nitrogen, operating from -50℃ to +250℃. For installation instructions, please refer to the technical documentation. 
Model with paired connector: When paired with a connector, add “C-” to the beginning of the ordering number, for example: C-GV-S16-SL.