Abstract: A male potency device comprises a ring member adapted to surround the male genitalia having at least one pair of metallic surfaces of metals having different electrode potentials on its internal circumference, said surface being adapted to remain in contact with the male genitalia when the device is worn; and adjusting means whereby the circumference of the ring member may be varied. Preferred adjusting means comprises a rotatable section of the ring member which is rotatable with respect to the ring member and is maintained in engagement therewith by at least one screw coupling, the degree of rotation of the screw coupling(s) serving to determine the variation in circumference of the ring member.