Abstract: A miniature magnetic, mercury-wetted relay construction for achieving optimum magnetic reluctance in its operating flux path and thereby improving relay sensitivity. The dimensions of the armature of the relay are determined for maximum flux-carrying capacity without sacrifice of flexibility by mounting the armature to the relay stem by means of a thin, magnetic hinge. At the pole-piece end of the relay, a recess is provided within which the contact is mounted, the recess forming a flux concentrator projection of the pole-piece which extends outwardly therefrom toward the opposing face of the armature. Reluctance of the flux closure path is further reduced by providing an integral extension of the stem toward the end of the pole-piece which extension advantageously acts as a parallel flux path shunting the small gap presented at the armature end and an end of the stem. By forming the shunt extension integrally with the stem, joint reluctance is eliminated.