The 19″ computer plug-in unit 4 U EVO 2.0 is suitable for the mounting of telescopic rails, HUB’s (card readers, USB connectors,etc.), internal drive holders (not in connection with an extended ATX mainboard), a PS/2 or redundant power supply, a fan (by the means of cuffs or a holder) or 3 additional fans (40 x 40 mm) to the slot insert at the rear panel. The mounting and dismounting of the drive support can be done very quickly and the fan can be assambled and disassambled without tools. The ventilation is optimised, so that the maximum ventilation capacity is reached and the filter pad can easily be changed from the front. The construction is EMV compatible. There is protection against access for devices and controll panels. The “Evo 2.0” is characterized by its high stability and it complies with all ATX form factors.