Inficon adapters are 90 Degrees and are for KF-25 to PVC Steel Spring Reinforced Hose. The flange size follows ISO-KF standards and is KF25 NW-25. The other end fits to a PVC ID Steel Reinforced Hose of 1 inch ID. They are commonly used to make connections between ISO-KF fittings and PVC Steel Spring Vacuum Hoses. The ISO-KF flanges are often called quick flange fittings because they are quick to assemble. A hinge clamp and centering ring form the vacuum seal between the connecting flanges and a hose clamp around the PVC hose. 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. They are made of Stainless Steel.