1. Copper is particularly suitable as a heat sink due to its excellent thermal conductivity, providing good passive cooling for Raspberry Pi 4. 2. 16 pieces of heat sinks cover the CPU, RAM, USB control module, and network module. 3. The back of each heat sink has thermally conductive adhesive, you can easily attach them to the board. 4. Copper is particularly suitable as a heat sink due to its excellent thermal conductivity. These heat sinks are all made of copper, which can provide good passive cooling for Raspberry Pi 4. Color: gold. Material: copper. Size: 15x15x5mm; 14x9x5mm; 8x8x4.5mm; 5.5x5.5x4.5mm. Package contents: 16 x Metal Copper Heat Sink. Only the above package content, other products are not included. Note: Light shooting 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.