A Closer look
The 9900 NT is made of copper which has been anodized to achieve the above look. The fins have been arranged in a circular fashion along the fan, which has been sandwiched between the two heatpipe rings. One side of the cooler utilizes four heatpipes while the other makes due with two. All six heatpipes end in the cooler base.
Zalman has polished the base quite nicely. The anodizing process does the rest to create a mirror like surface area to dissipate heat away from the CPU. Six heatpipes are sandwiched between two plates on the base of the cooler. Zalman has chosen to make these pipes short, so that they do not go across the entire base, encasing them within the metal plates. While this is a good design choice, it does reduce the actual area for which the pipes transport heat away from the CPU.