Normally a water block presses against the CPU heatspreader, but this one is a bit different. MSI and Thermaltake decided to team up and make a motherboard-specific cooler that pulls heat away from the CPU and the motherboard's VRM MOSFETs. This way, water chills both the CPU and its power delivery, which could be a bottleneck when overclocking.

Specifically, the Thermaltake Pacific M3 motherboard water block is designed to be used with the MSI Z170A Gaming M5 motherboard. This is a Skylake / DDR4 platform with USB 3.1 and SATA Express.

Note that this is not a closed-loop cooler. It is designed to be embedded in a custom cooling loop, which means that the user (or a small business computer store that maintains their PC) is responsible for routing water and preventing leaks. That said, users who are looking for a high-quality cooler for their power delivery system should expect a little commitment to their build (and a little risk).

Also, since the product is designed for a specific motherboard, the user shouldn't expect to keep it hanging around from build to build. You will almost definitely use it while you have it and leave it when you move on. On the other hand, you shouldn't worry about it covering your RAM or anything — you can be reasonably assured that it's built for your setup. (That is, unless you buy the wrong motherboard or something… d'oh!)