These KF to Tri-Clamp (sometimes called Tri-Clover) adapters are designed to bridge vacuum and sanitary systems seamlessly. Made of 304 stainless steel, they come in a variety of sizes to fit your particular appliation. The ISO-KF flanges are often called quick flange fittings because they are quick to assemble. A circumferential clamp and centering ring form the vacuum seal between the connecting flanges. The centering ring contains a rubber elastomer o-ring. The standard sizes for quick flange fittings are KF-10, KF-16, KF-25, KF-40, and KF-50 with flange sizes NW-10, NW-16, NW-25, NW-40, and NW-50, respectively. Tri-Clamp fittings are measured by the outer diameter of the tube and not the OD of the ferrule. Tri-Clamp style fittings also use a differnt type of O-ring gasket than KF, and will need to be purchased seperately in order to make a complete connection.