1.【Raspberry Pi 4B Heatsink】: The Heat Sink is specially designed for the Raspberry Pi 4B and fits perfectly. | 2.【100% Copper Material】: Adopts high quality pure copper material, the thermal conductivity of copper is much more efficient than aluminum alloy, and the groove design greatly increase the heat dissipation area, the accumulated heat can be released into the air faster. | 3.【Quiet Operation】: Unlike cooling fans, there is no operating noise, so you can work without disturbing your concentration. | 4.【Easy Installation】: Comes with a special thermally conductive sheet that can be easily installed by simply pasting it. (Normally, the thermal pad is shipped attached to the heat sink, but if it is not pre-attached, please peel off the protective film on both sides of the thermal pad when installing.) | 5.【100% Satisfaction Guarantee】: Haojiaho is committed to providing customers with high quality products and service. Customer satisfaction is our top priority. If you have any issues (including damage, functionality issues, missing items, incorrect colors, or package non-receipt, etc.), please contact us in time to get a new replacement or refund, and we will reply to you within 24 hours.