Cooling fan device for a computer

A cooling fan device for a computer, comprising:

• at least one fan device having a primary housing, a side housing, and a fan;
• the primary housing has an area of ventilation holes located through an exterior surface thereof, a sink located on a back surface thereof for latching with the fan, a plurality of insertion slots located on a first side thereof, and a plurality of projection parts located on a second side thereof;
• the side housing has a plurality of insertion pieces protruding outwardly from an interior thereof and inserted into the plurality of insertion slots, and a flexible press plate located on a side of the side housing, the flexible press plate has a transversal flange part and a locking slot located on a surface thereof;
• and
• a computer casing has a side wall having an area with a plurality of air permeable holes, right positioning slots located in a right wall relative to the area with the plurality of air permeable holes, and a left positioning slot located in a left wall relative to the area with the plurality of air permeable holes,
• wherein the plurality of projection parts of primary housing are latched into the right positioning slots, and the flange part on the press plate is latched into the left positioning slot, the fan device is selectively connected to and removed from the computer casing.