Made of Aluminum and copper, good thermal conductivity, can reduce the risk of failure due to overheating. The fins increase the area of the board, let a maximize surface area with the cooling air thus provide for greater heat transfer, also they have profiles which are short enough to fit within the cases. Compatible with Raspberry Pi 3B. Feature - Color: White. - Material: Copper+Aluminum. - Size: 1.50X1.50X0.60cm/0.59X0.59X0.24in Blue Aluminum Heat Sink(3 Pieces): 9 * 7 * 12 mm / 0.3 * 0.2 * 0.4 inch Black Aluminum Heat Sink ( and Two Small): 14 * 14 * 6 mm / 0.5 * 0.5 * 0.2 inch ( ) 9 * 9 * 5.2 mm / 0.3 * 0.3 * 0.2 inch (Two Small) Silver Aluminum Heat Sink ( and Two Small): 14 * 14 mm / 0.5 * 0.5 inch ( ) 8 * 8 mm / 0.3 * 0.3 inch (Two Small) Copper Heat Sink(3 Pieces): 14 * 12 * 5.5 mm / 0.5 * 0.4 * 0.2 inch - Double-sided thermal transfer tape, offers high thermal conductivity and long lasting adhesion in all mounting scenarios. - Higher thermal conductivity, Copper Heatsink thermal conductivity higher than Stainless Steel Heatsink, Aluminum Heatsink thermal conductivity higher than brass heatsink. Our product are made by Copper and Aluminum, have more better thermal conductivity. - The fins increase the area of the board, let a maximize surface area with the cooling air thus provide for greater heat transfer, also they have profiles which are short enough to fit within the cases. - Fit for Raspberry Pi 3B, the Processor, Memory chips, LAN 9514 Chips and other chips. Easy to install, easy to use. Package list: 3 x Blue Aluminum Heat Sink 3 x Black Aluminum Heat Sink ( and Two Small) 3 x Silver Aluminum Heat Sink ( and Two Small) 3 Heat Sink