FrostyTech posted a review on the Noctua NH-U12 Low Noise Heatsink

The Noctua NH-U12 is a large 155mm tall heatsink that resembles a Soviet-era apartment block. The Noctua NH-U12 heatsink comes with all the necessary mounting hardware, but no fans are included. Mounting clips will allow users to install a 120mm fan on either side of the unit if they desire, but we found a single 120mm fan more than sufficient for the job. The 38 nickel-plated aluminum cooling fins are connected by four copper heat pipes to a copper base plate that pushes the overall weight to around 700grams.

Noctua NH-U12 Low Noise Heatsink Review