Of the twelve copper fins, the two middlemost ones are twice as thick as the others.  This is an effort to pull more thermal energy directly up off the processor.  You will also notice the large ribs cut into the sides of the fins.  These ribs will help generate some turbulence adding to the sink's cooling efficiency. 

The outer most fin or bracket if you will, on each side is double thick aluminum and functions as a fan mount.  Small holes on the top section allow air to pass through the side piece where it tapers in.  I'm not sure exactly what the point of this is as if the holes were not here the velocity of the air being pushed over the fins would increase which to my thinking would make better cooling possible.  It could be an effort to circulate air under the the sink on the sides of the socket to move the stagnant hot air away.  One other thing about the sides; they are a hair taller than the fins themselves which will elevate the fan over the fins in such a way as to eliminate the "dead spot" directly underneath the fan's motor.

Down the middle of the fins a trench is cut making room for a three latch clip.  The three latch per side clip gripping each of the socket lugs is far superior to the old one lug per side method.  One side of the clip has an oversized thumb area allowing you to open and close the clip at an elbow on that same side.

Here we get a better view of the base and how the alternating copper and aluminum fins and spacers look.  The base itself was smooth to the touch but lacked the mirror high polish finish seen on other coolers.  Keep in mind though that this is an $18 product.

The included fan is a 70 x 70 x 25mm number rated at 3800 RPM and 36.5 dBA while moving just under 32.5 cubic feet of air per minute.  The fan was a bit louder than I expected at 36.5 dBA.  While not exactly loud enough to get an eye squint, it was loud enough that it could easily become irritating to some.  Provided it was mounted on a mainboard with an onboard fan speed control within the BIOS, it would be tolerable in most any situation.  If not, while it may not keep you awake at night if your PC is by your bedroom, it will make you toss and turn a bit.

Installation

Installation of the A8641-L was clean and trouble free.  The size of the cooler didn't present any mounting problems and its footprint is such that I would be very surprised if a K7 mainboard exists it wouldn't fit.