ITEM NAME:30x Heatsink Copper Shim 15mmx15mm for Notebook Laptop GPU CPU 6 Sizes D CMY Description Features: 100% brand new and high quality 30pcs Laptop GPU CPU Heatsink Copper Shim Material: Copper The copper has high purity , coefficient of thermal conductivity as high as 401w/mk . It can be applied to computer and all laptop and computer heatsink solution . Specific methods of operation : The original graphics chips generally has a thermal conductivity about 2MM ,lapsed after a long time, after finish BGA , replace this with a copper sheet. Turn the function of fan from thermostat to running ,remove the yellow line directly, the red line of fan connect to the USB.30pcs Laptop GPU CPU Heatsink Copper Shim. It can be applied to computer and all laptop and computer heatsink solution. 30 x Copper Heatsink. Material: Copper. The copper has high purity, coefficient of thermal conductivity as high as 401w/mk.