Nuts can be MF, FF, MF with brass material. Diameter can be 1/2", 3/4" etc. Length can be customerized. Body material is 304 stainless steel with PE cover. Features: 1. Easy installation 2. Firm connection 3. Corrosion resistant 4. Stable gas flow 5. High flexibility 6. Long service life 7. Be bent freely without any crack Application: City gas, LPG, Natural gas, firedamp etc.