1. Copper is particularly suitable as a heat sink because of its excellent thermal conductivity, provide good passive cooling for Raspberry Pi 4 2. 4 piece heat sink cover CPU, RAM, USB control module and networking moulde 3. The back of each heat sink has thermal conductive adhesive, you can stick them to the board easily 4.Copper is particularly suitable as a heat sink because of its excellent thermal conductivity. This heat sinks are all made by copper, can provide good passive cooling for Raspberry Pi 4 colour: gold Material: copper size: 15x15x5mm;14x9x5mm;8x8x4.5mm;5.5x5.5x4.5mm Package Contents: 8*Metal Copper Heatsink 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.