The 100318803 Flange Toggle Clamp is used to join NW25 size ISO-KF vacuum flanges. This aluminum toggle clamp is convenient and easy to use with enough sealing force to fully compress the O-Ring, so that the flanges and the centering ring are metal to metal. The heavy-duty spring supports the full range of production tolerance variables with the self-adjusting clamp locking in a positive method. A pin can be inserted to prevent accidental release of the toggle lever. The toggle clamps are ideal for situations where the clamp must be removed frequently, like leak testing or gauge calibration. 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.