Saim Heatsink Copper Shim Thermal Pads for GPU CPU VGA IC Chipset 15mmx15mm Pack of 40(8-Size) Easy installation for your DIY arduino projects,with good heat dissipation effect Material: copper; With this copper pad to greatly lower GPU temperatures, can be used for graphics, northbridge, CPU chips. It can be applied to HP, Dell, Acer, Thinkpad and all laptop and computer heatsink solution! How to use: First daub a little thermal silicone grease (FYI: Do not use the low-end silicone grease), then put the right size copper shims, then daub a little thermal silicone grease again, last install the heatsink and tighten the screws Package included: 40 x Copper Thermal Heatsink(8-size).