This is din standard nut with slots, easy to assembly, it is popular in Europe on certain winery and brewery equipment or systems. They do not interchange with Tri-Clamp or Acme threaded sanitary fittings. There is DIN11850 and DIN11851 of unions, DIN11851 is with a long welded liner, and the pipe O.D in DIN standard is often bigger than SMS/3A standard. The nut is made of SS304 stainless steel in food grade finish, the nut, liner, male and gasket assemly a union set. We have LG Mazak CNC machine, that we can provide you the high precision and excellent bpe grade finish.