The Hydro Series H45 makes your PC run cooler & quieter when you replace your CPUÂ’s stock heatsink. The compact components & flexible tubing make the Hydro Series H45 easy to install even if youÂ’re cramped for space. It means that you can improve your CPUÂ’s cooling efficient even in the most compact cases Â- as long as your case has a 120mm fan mount near the CPU, the H45 will probably fit. The H45 comes pre-filled, & never needs priming.