Product Description: The Model 1.5 Spacer is 6" square and the base is gently rounded to prevent gouging the roof. The outer edges are raised 1-1/2" and increased elevations may be achieved by stacking Model 1.5 on 1or 2 spacers, each with a height of 1-1/2". Four drainage ports are provided to prevent ponding within the device. The dimensional area resting on the roof is 5-7/8 inches square and 34.52 square inches exist of contact roof support.