The Xigmatek Loki
Figure 3 shows the cooler from the front. Here you can see the border fins are irregular.
In Figure 5, you see the side of the heatsink. The folded fins make an almost completely closed surface.
On the top of the heatsink, shown in Figure 6, you can see the slots for installing the fans on both sides. The tips of the three U-shaped heatpipes are also visible.