In this paper we reveal common features in the constructions of some compacta with . To any regular -space a class of regular -spaces is related. Elements of are called tailings of . Two concrete types of tailings are described. For any compactum with , these constructions allow to obtain compacta with and .
At the end of the paper, using tailings, we present compacta with different dimensions and constructed by means of product formation starting from compacta with equal and .