That is the DC-LT 3600, the noisy one that OptimumTech recommended against and nobody wants. His words exactly "you want to stay away from the faster 3600 RPM model it is very loud." Why did you buy that one?
Oh and it is also very much in stock (as expected for a noisy one) https://www.amazon.com/Alphacool-13154-Hexagonal-15-5-17mm-Cooling/dp/B007ENAV3W