1、The surface is easy to produce a dense, strong protective film that protects the substrate from corrosion, is lightweight and durable, and has high abrasion resistance and prevents rust. 2、The housing can be equipped with a cooling fan. The hollow design makes heat dissipation more efficient and protects the motherboard. 3、The outer casing and the main board are closely matched, and the various interfaces are of uniform height, the holes are accurate, and the disassembly is convenient. 4、The aluminum alloy casing is slotted and does not affect WIFI/Bluetooth signal transmission. 5、High hardness, high pressure resistance, metallic luster, and rust-free aluminum alloy materials are more conducive to heat dissipation. Features: The surface is easy to produce a dense, strong protective film that protects the substrate from corrosion, is lightweight and durable, and has high abrasion resistance and prevents rust. The housing can be equipped with a cooling fan. The hollow design makes heat dissipation more efficient and protects the motherboard. The outer casing and the main board are closely matched, and the various interfaces are of uniform height, the holes are accurate, and the disassembly is convenient. The aluminum alloy casing is slotted and does not affect WIFI/Bluetooth signal transmission. High hardness, high pressure resistance, metallic luster, and rust-free aluminum alloy materials are more conducive to heat dissipation. Specification: Item Type:Case Material:Aluminum Alloy Fit for Raspberry Pi 4 Size:9.5 x 6 x 3cm / 3.74 x 2.36 x 1.18in Color:Black Package List: 1 x Aluminum Alloy Shell (Including 4 Accessory) 11 x Fixture Screw (10 x Black 1 x Silver) 1 x Fan(1 x Fan 3 x Screw 3 x Nut)