DAOKI 15 PCS One Set Aluminum Heatsink Cooler Adhesive Kit Sink for Cooling Raspberry Pi The Heatsink have a layer of adhesive on the back of them. Simply peel the adhesive off and stick onto your board This heatsink set is specially designed for Raspberry Pi, it's function is to cool down the board and make your Raspberry operate safely Reduce the risk of hardware failure because of overheating Package included: 5 set of aluminum heatsink (3pcs)