Hoffman CP4420, CONCEPT¢ Panel, 42.20x18.20These panels are taller and wider than corresponding NEMA-size panels. Panels are 14 or 12 gauge steel and painted white or have a conductive finish. Panels have a formed flange along any side that is longer than 22.20 in. (564 mm). CP2420 and CP2424 have a flange on all four sides.