Mersen Class H and K fuse blocks accommodate all Class H and K 250 power fuses. A choice of screw, pressure plate, box and special order stud connectors fit a wide range of stranded or solid copper or aluminum wire. Insulators are molded glass-filled polycarbonate (GFPC) with verified dielectric strength in excess of 2500V. 30, 60 and 100A fuse blocks feature a unique adder block which can be snapped onto 1, 2 or 3-pole blocks to form multi-pole segmented blocks of as many poles as desired. All fuse clips are made of high conductivity tin-plated copper, with a choice of non-spring reinforced clips in 30A. 30 Ampere current rating. #10-14 Wire Range. 3 Pole.