The 100313514 Conical Reducer is used to reduce a NW40 size ISO-KF vacuum flange to a size NW25 ISO-KF flange and is made of aluminum. This flange size reducer features a high conductance conical between the two flange sizes. Series 31 ISO-KF vacuum components are designed for use at sub atmospheric pressure and use standard interface dimensions defined by the International Standards Organization (ISO) allowing them to be interchangeable with other ISO-KF compliant components. Series 31 components can be used as modular building blocks to create vacuum piping systems. IS-KF flanges are "sexless" with a symmetrical seal so that so that components are rotatable. ISO-KF vacuum flanges are joined by inserting a centering ring between the two flange faces, and securing them with a flange encompassing clamp.