The Agilent 911D sliding load represents an advance in calibration and verification of network analyzers. It utilizes integral connectors to form a near perfect airline without the discontinuities associated with changeable connectors, which cause reflections. The load element is highly stable with a reflection coefficient variation of less than 0.00032 as the element location is varied, greatly increasing the integrity of a calibration. A locking mechanism is used to locate and lock the center conductor reference plane to within 0.00005 inch of the outer reference plane.