We have a D-Tek Pro Combo to try out. The combo is comprised of their nicely painted Pro Radiator with their venturi shaped fan shroud. Shrouds are very important as they increase the distance between the fan hub and core, thus eliminating a dead area. They also help direct airflow through the entire 6” x 6” (152 x 152mm) core as opposed to just attaching a 4.75,” 120mm square fan directly to the core.