StarPro's 15'x20' 5-Hole Professional Practice Putting Green. Pat.No. 6,287,213 15' x 20' putting green StarPutt Turf: 48-oz face weight; 90-oz gross weight per square yard; 3/4" twisted two-color nylon face - heat set to 1/2" Durable, UV-stabilized, non-directional surface 2 mm rubber base under the five-layer action back gives a great golf feel and bridges sub-surface irregularities for breaks and easy installation