Most conventional borders still have to be considered fully enclosed "24V DC Cooling Fan", ordinary, law-abiding, from the suction side of the fan, and then allowed to stay more concentrated flow along the border. However, recently this has also been a fan border changes, the use of a circular frame with sunflowers type "24V DC Cooling Fan" to more uniform cooling. There are even designed to narrow the width of the shape, so that the air flow is more concentrated. "24V DC Cooling Fan" surrounded by open frame design is actually derived from a fully enclosed, like Venus 10A Tt is a fan of this design. This increases the range of the fan inlet, thereby increasing the fan air flow.