Unique Hollow blade design by GST is unlike anything on the market. The hollow vein in the center of the grass blades makes up not only for the truly realistic look of the grass, but also supports its ability to keep the temperature of the lawn stable and cool in hot climates. In plants, leaf surfaces are dotted with stomata (openings or holes) bordered by guard cells that open and close the pore. Transpiration, a process that cools plants, occurs through the stomatal apertures. Transpiration serves to evaporatively cool grass as the escaping water vapor carries away heat energy. Hollow blade technology mimics the same process, which helps to keep moisture inside stems longer and, therefore, lessens the temperature of a lawn.