There are provided arc quenching plates for leading an arc formed by operation of electric contacts away from the contacts, and there is provided a housing for holding the arc quenching plates. The housing has grooves made into opposing internal walls, and the grooves extend from a first side of the housing for a predetermined distance into the housing, the arc quenching plates are insertable from the first side of the housing into the grooves, and a retaining plate holds the arc quenching plates in place in the grooves. The retaining plate may have an exhaust channel between the housing and the retaining plate for exhaust of arc gases in a direction substantially parallel to a plane of the retaining plate, and substantially perpendicular to a plane of the arc quenching plates.