This piece is to create concrete cover in double layered slabs. It consists of two parts ( base and shaft), that are coupled to one another. The first part (base) has a fixed height of 30mm. with four coverage distances of 25, 30, 35 and 40mm. ,and the second part (shaft) come in nine heights to give (40, 50, 60, 70, 80, 90, 100, 110 and 120 mm.) concrete coverage. This spacer is made to replace bolster, thus eliminating the use of chair spacers beneath the first network which is considerably cost effective