Features: 1.Tailored for Raspberry Pi 4B. For Raspberry Pi 4B and 3B+/3B have different interfaces, and the shells are not universal. 2.Passive heat dissipation of the whole shell. The heat of the for Raspberry Pi CPU is transferred to the aluminum alloy shell through the heat conduction column, and the dual fans further enhance the heat dissipation effect of the aluminum alloy itself. 3.Aluminum alloy shell, metal heat sink, the whole is hard and beautiful, lightweight and durable, and the metal stripe design allows the temperature to be more effective in a shorter time. 4.The tail of this aluminum alloy shell is slotted, which does not affect the wifi/for Bluetooth signal transmission. 5.This shell is designed with GPIO position opening, camera connection port, Poe interface hole, digital?speech interpolation display connector interface hole, which is convenient for GPIO pins to plug and unplug without opening the cover. specification:Item Type: Aluminum Case with Dual Fan Material: Aluminum alloy Application: For Raspberry Pi 4B PackageList:12 xScrew1 xHex Wrench1 xFan4 xThermal Silica1 xAluminum Alloy Shell Upper Layer1 xAluminum Alloy Shell Lower Layer NotePlease note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.