Feature:1. Sandblasted And Oxidized Surface: The surface of aluminum alloy is sandblasted and oxidized, which is corrosion resistant, moisture proof and rust proof, and has a long service life2. High Heat Dissipation Efficiency: Aluminum alloy integral die casting molding, smooth surface without burrs, strip convex design bring high heat dissipation efficiency3. Easy To Install: Screw assembly is simple, easy to install, convenient to operate and carry4. Used With Expansion Board: This cooling shell can be used with any for Raspberry Pi 4th generation expansion board5. Excellent Performance: Metal box for Raspberry Pi 4B have stable structure, excellent performance and long service lifeSpecification:Item Type: Shell for Raspberry Pi 4BMaterial: Aluminum alloyColour: Black.Package List:1 x Shell for Raspberry Pi 4B1 Pack of Fastening Screw