Abstract: An electric overcurrent and short-circuit protection device which utilizes a pair of horn electrodes with a fusible conductor connected therebetween. The electrodes are arranged, together with suitably adapted insulating walls to form a first arc-quenching chamber with the walls of said chamber spaced apart by a predetermined narrow gap extending in the plane of the electrodes for a predetermined distance. The walls have a plurality of holes therethrough, which have a predetermined length and diameter. This inner chamber is arranged within a second quenching chamber, at least one wall of which is provided with holes therethrough.