With Prolink's graphics card, PDF means cooling for components and the colorful LCD display. This display shows the temperature as well as the rotation speed of the fan and is called "Blue Icy Display." This can also be removed and built into a 5.25" panel via an extension cable. Prolink provides all of this in the package.
In one of the instruction leaflets that come with the graphics card, the manufacturer mentions that the measuring tolerance is about 2°C and approximately 250 rpm for the fan. Unfortunately, the manual is not very detailed and refers to the entire GeForce-FX family. A more customized handbook containing all the answers to your questions would have been more helpful.
According to the manufacturer, the all-metal casing is supposed to bring advantages when cooling the components. However, the card's factory-set clock speeds aren't very high anyway, so cooling is not really an issue to begin with. The metal casing also has a disadvantage: if your motherboard is equipped with a lock mechanism for the AGP slot, you might very well have difficulties opening it.
Cool blue: both the fan and the LCD display light up in blue