I hadn't heard of a HSF manufacturer by the name of Fortis before, but here you go. Overclocked Cafe has a review posted of a Fortis A102 HSF. here's a snip:

"The copper base is 5mm thick, and the fact they used aluminum for the fin design keeps the weight down to minimal. they've also "built" the aluminum around the copper base, using a rod that runs through the body of the heatsink, and then riveting it secure (see middle picture below). What it does is help to "seal" the copper base, into the aluminum shell. This where a lot of manufacturers falter, trying place a piece of copper inside a cut out in the aluminum isn't going to get the job done - there will always be a gap between the copper and aluminum when it is done that way (Confucius say trying to squeeze copper base plate into aluminum cut-out like two male dogs humping - it look like it work but they beat head against wall). You can squeeze as much paste as you want to fill it the gaps, but it's not going to work. it's best to get an ice bucket, and shove cubes in between, it's your only shot at keeping it cool."