well i did a custom one. bought a 3in x 8ft aluminum dryer duct from Lowes. ALl i did was make the shape i want and duck tape the crap outta it. I did get cooler degrees, from like 33.5 C to 30 C. w/ 55cfm smart case fan. But overall, it looks like crap in my case. I have a chieftec x-pider so the side fan is under the cpu area and the duct hits the radeon card. So i had to use the intake fan from the front of the case, which made it extra long. The longer the vent, the lesser the airflow performance. My roomate did the same mod on his Xaser III case and the it gave him 4 degrees cooler and his intake fan is right on the CPU hsf so it was just a straight pipe to the cpu. So it depends, but it did cool it down a tad, but not enough to make me realize how ugly the pipe looks in my case lol. peace