International standard EI-Lamination which is used for transformers EI CORE:Single phase size: EI-28, EI-30,EI-35,EI-38.4, ... -168,EI-190.5,EI-228, EI-305 etc.Three phase:EI-80,EI-100,EI-160, EI-122,EI-152 ... ,H-50, H-20, H-18, Z11 Pls contact us for the detail.