Abstract: An electrical contactor comprises a rectangular base carrying at least one pair of spaced fixed contacts. A movable support element carrying movable contacts is disposed on the base. A prismatic casing open at both ends is disposed on the base. A solenoid disposed within and supported by the casing comprises a movable armature having two parallel legs directed towards the base with their free ends resting on the movable support element. Two arms are hinged to the base near diagonally opposed corners of the base and have inwardly-directed projections arranged to engage diagonally opposed corners of the end of the casing remote from the base when the arms are pivoted against the casing. The inwardly-directed projections are provided with threaded holes.