Best value and quality for a P4 heatsink (IMO).
It has a full copper heatsink with a smart fan - i.e. it can be controlled by temperature (via an included probe), or with a controller (also included - mounts in PCI slot). I used to have this heatsink and found it to be really worth the $35, but now I have water cooling .
Hope this helps!
If you want to really overclock but don't want to pay for watercooling...may I recommend this?