Two "Mini Air Cooling Fan" is usually used in dual fan radiator, both with the same parameters and specifications of products. And combinations thereof in the form of no more than two in series and in parallel. Parallel dual fan heat sink each responsible for a part of air work, you can get a single fan air volume nearly twice. Series of double "Mini Air Cooling Fan" usually with duct design of heat sink, using a suction blow a design purpose is to increase pressure, increase the amount of wind in disguise (dual fan heat sink shared drag, each one to overcome the static pressure difference will be substantially reduced, the amount of wind has increased,). Thus through the air fins can be very smooth through, drag to a minimum, the heat exchange efficiency has been greatly improved, but also to avoid the aforementioned side-mounted on the other side radiator cooling fins uneven shortcomings, the advantages of side-mounted on its head! Cons: As a result of the two "Mini Air Cooling Fan", corresponding noise doubled, costs also increased a lot, if you are using the side-mounted design, it is more difficult to control the volume.