When I hear the name ZEROtherm it immediately takes me back to seeing the images of the “butterfly cooler” all over the net. This copper and red CPU cooler was quite the step away from the “norm” of cooler manufacturing and has put ZEROtherm on the map. The BTF series of coolers were brought up as that cooler shows how the company took a basic idea and kept improving upon it until they had an effective all copper version with a 92mm fan, eventually replacing the 80mm they started with.