GideonTech has reviewed the Cobalt3 Pyramid II Fan Silencer :
At the current state of case modding and cooling, fan and bay buses are as common as screws in a case. Everyone knows the benefits of using these bay controlling devices to monitor and tune fans and other items within a case. With demand comes innovation, which is what Cobalt 3 has provided. They have created a fan device that automatically speeds up a fan when it is needed and speeds it down when it is not. Let's take a look at their Pyramid II.
The Pyramid II is simply a device that takes over the job of a fan/bay bus. Instead of manually flipping switches and turning knobs, this little device has a temperature probe at the top that controls whether to speed up or speed down your fans