That screaming fan says something...

The 38mm Delta fan is like a little turbine engine on top of this cooler.

It's noisy, it's speedy, and it cools like no other fan would. The fan features focused flow capabilities by using a set of nine stationary fins built into the fan body itself.

The seven bladed impeller is essentially the standard to what you might expect to see on a 25mm fan, and is not really any deeper than normal, so the remaining height of the fan is taken up by the flow directors. The nine fins are arranged in the opposite direction to the impeller and help to direct the 45CFM worth of air flow directly downward.

Dynatron ship the Model-638 with a nice chrome fan grill attached. It should be noted that while most of the time fan grills are really just for show, in this case it's serving a very real purpose.

Now, when we review heatsinks they generally get taken to pieces several times before the review is complete. Unfortunately I also removed the fan grill for a moment and the 38mm Delta managed to take a nice sized bite out of my finger in the process.

That's real blood, and yes I know I should have put the damn grill back on before powering up the beast, but hopefully you'll learn the lesson I overlooked in my haste.

Thin Copper Fins:

The copper fins are thin and connected to the base by means of thermal adhesive (from what we can see). Although they appear to be skived from the side, this is more slight of the hand than anything else.

The side of the copper base is slightly brought up and this obscures the joint between the fins and the base.