Features: 1.With external slot, the aluminum alloy case does not affect the transmission of wifi/Bluetooth signals. 2.Built-in hot column, the housing can be equipped with a cooling fan, built-in hot column, and heat dissipation is more effective. 3.The surface is easy to produce a dense and strong protective film to protect the substrate from corrosion, light and durable, wear resistance and easy to embroider. 4.It is made of aluminum alloy material, treated by oxidized sandblasting, smooth and non-convex, high hardness, pressure resistance, strong metallic luster, not easy to rust, and aluminum alloy material is more conducive to heat dissipation. 5.Excellent process to ensure perfect size, this housing is suitable for Raspberry Pi 4. specification:Item Type: Case Uses: Case for Raspberry Pi Material: Aluminum Alloy Applicable Models: For Raspberry Pi 4 Product Size: Approx. 8.5 x 5.5 x 2.5cm / 3.3 x 2.2 x 1.0in Color: Red, Blue, Gray (Optional) PackageList:Case x 1Heat Sink x 2Hex Screwdriver x 1Screw x 4