The 100314913G Bellows Hose features a size ISO-KF NW25 vacuum flange at each end and is made with 321 stainless steel. This bellows features a thin wall formed metal spring design allowing it to be compressed to 3.07 in. from its 3.94 in. extended length with a 44 lb./in. spring rate, and bent with a 1 3/8 inch static bend radius. Bellow vacuum hose is a great solution when straight line plumbing is not possible, vibration isolation is needed, or for creating rough plumbing lines. 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.