The cores are wound from thin Grain Oriented silicon steel strip and are annealed in high vacuum furnace under protection atmosphere. The impregnation is done in vacuum impregnating equipment, low-stress and high-viscosity resin is being used. Fine polishing process of cutting surface ensures that the cores have excellent match. The cores have accurate dimensions and high permeability, widely used in AC/DC measuring clamp meters with Hall components. Applications: AC/DC clamp meters, current transducer, inductor, magnetic aplifier etc.