Abstract: A trigger assembly for parts checking jigs and the like has a pivoting trigger arm with a central bearing aperture. A universal base is supported on the jig, and has two pairs of pivot pin apertures located adjacent opposite ends, a U-shaped central channel in the bottom face in which the trigger arm is received, and two laterally spaced gauge bushing apertures in the upper face. A pivot pin extends through the bearing aperture in the trigger arm and one pair of the pivot pin apertures in the base. A spring is mounted in the base and biases the trigger arm to an extended position. A gauge bushing is received in one of the two bushing apertures, such that the trigger arm assembly can be readily reconfigured for placement at various locations on the jig by selective mounting of the trigger arm and the gauge bushing in selected ones of the associated base apertures.