1、Adopt aluminum alloy material after oxidation sand blasting treatment, smooth and not convex, possess high hardness, pressure resistance, strong metallic luster, not easy to rust, more conducive to heat dissipation 2、All ports and slots of the case can perfectly match for Raspberry Pi 4 Computer Model B 3、The external slot of the aluminum alloy shell will not affect the transmission of wifi/for bluetooth signals 4、Built‑in heat column, shell can be equipped with cooling fan(without fan), heat dissipation is more effective 5、Using a silicon thermal pad (only 0.5mm thick) to touch the housing for cooling. You can use CPU grease to loosen the silicon gasket for better heat dissipation 1 x For Raspberry Pi 4 B+ Case(without fan)1 x Screw Pack Item Type: For Raspberry Pi 4 B+ CaseMaterial: Aluminum alloyColor: RedType: ShellCompatible: For Raspberry Pi 4th generation b+Features: Passive cooling architecture designs can achieve perfect heat dissipation