Tile positioning cross usage: Under normal circumstances, a brick with a cross, 5mm cross can be used after the bricks are almost the same, can be used three times, which can save some costs; but 3mm and 2mm cross is not easy to take Underneath, otherwise it is easy to buckle off the bricks. Only when the bricks are completely dry can they be taken down, so it is generally difficult to reuse. If you don't want to take them, you can't see them after filling them. It is recommended to follow a piece of brick with a cross. Purchase in principle.