Features: brand new and high quality The copper has good thermal conductivity , can provide good passive cooling for Raspberry Pi . Each heat sink has self stick thermal conductive adhesive , you can stick them to Raspberry Pi directly. 4 piece of heat sink can provide cooling for both CPU ,USB control module and nerwork module. Passive cooling architecture design can reach perfect heat dissipation. 4 pieces set heat sinks on PCB board for better heat dissipation.. Specifications: Material: Copper Color: As Pictures for: Raspberry Pi 4 Model B Size: approx 15x15x5mm/ 0.59x0.59x0.2in 14x9x5mm/0.55x0.35x0.2in 5.5x5.5x4.5mm/0.22x0.22x0.18in 8x8x4.5mm/0.31x0.31x0.18in quantity: 4 PCS/ 1 Set Note: Note: Raspberry Pi board is not included. Due to the problems of lighting effects and shooting angles, there will be certain tolerances in the product, please understand. Please allow 0-1cm error due to the manual measurment Package includes: 4 PCS x Copper Heat Sinks ( not include Raspberry Pi)