This part of IEC 1021 specifies the electrical characteristics of laminated core packages using YEE 2 laminations according to IEC 740 and, in their larger variant, according to IEC 1021-1, for cores made from specified grades of oriented silicon-steel or nickel-iron alloys. It also gives the marking and packaging requirements. The main applications of these cores exclude the significant transmission of power with the consequence that the principal electrical characteristic may be expressed in terms of inductance factor AL. Although laminated core packages are produced with or without an air gap in the centre leg of the magnetic circuit, this part deals only with gaped cores, where control of the length of a designed air gap enables specified AL values to be achieved. NOTE — The electrical characteristics of laminated core packages without an air gap is a matter for agreement between customer and manufacturer.