Small and light aluminum alloy materialHigh hardness, metallic , not easy to rust, and durable aluminum alloy material is more conducive to heat dissipationThe Aluminum Case the metal shell is more conducive to heat dissipation, and comprehensively protects your motherboard. Full package and full protection After repeated testing, each hole is highly matched to the motherboard, and the protection is more thoughtfulSpecially made for raspberry pie 4b, raspberry pie 4b is different from 3b+/3b interface, and the shells are not common to each otherApplicable model: For 4BColour:blackMaterial:Aluminum alloyPackage Contents:1 x Aluminum Alloy Upper Cover1 x Aluminum Alloy Lower Cover3 x Thermal Pad1 x Wrench1 x Cooling Fan8 x ScrewOnly the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. Note: Please allow slight errors due to manual measurement. Please make sure you don't mind before bidding. Color may vary depending on your monitor, please understand. Note: Hello, please pay attention to your shipping address when purchasing products. If your delivery information (e.g. name, street, house number, doorbell/email without name, etc.) is incorrect, the order will not be delivered correctly