18732807193 Tree Grates size is generally 38 * 38 * 25, suitable for pedestrians. Tree pool cover glass steel grille design: 1. Measure the length of the Pits good size and diameter 2. Grate Tree tree needs two boards stitching. As a whole Pits size of 1 * 1, need to cut two boards stitching together 0.5 * 1 3. If the diameter of the tree of 20cm, required on the board 0.5 * 1, an intermediate position along the edge of the cut off 1m 20cm * 30cm the gap, after stitching together, we can ensure the tree grate in the middle of a block size of 30 * 30cm ^ 2