The 100315103 Full Nipple Fitting is a 3.94 inch (100 mm) long straight section with size NW25 ISO-KF vacuum flanges on each end. Our full nipple fittings are made with 304 stainless steel and are used as straight extensions of ISO-KF flanges in vacuum piping applications. Series 31 ISO-KF vacuum components are designed for use at subatmospheric 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.