Noctua NH-L9i Low Profile Heatsink
 

FrostyTech says the Noctua NH-L9i low profile heatsink is perfect for projects with extremely tight space constraints. If you are working on a small form factor system or HTPC, you might want to check out this review. Noctua's low profile NH-L9i heatsink stands 36mm tall so it will fit into the smallest of small form factor chassis. The NH-L9i is designed to cool Intel socket LGA115x (1155/1156/1150) processors only, which is a departure from the one-size-fits-all approach we're used to from heatsink manufacturers.

http://www.hardocp.com/news/2013/11/...file_heatsink/