The NM-TR5-SP6 is a SecuFirm2 mounting kit that allows the installation of Noctua's DX-4677, DX-4189, DX-3647 and TR4-SP3 series coolers to AMD TR5/SP6 sockets (sTRX5/sWRX9) for Epyc server and Threadripper workstation CPUs are possible. While the brackets and springs have been updated to meet the increased pressure requirements of the new TR5/SP6 socket, installation is just as easy as the previous generation: put on the heat sink, tighten the four spring-loaded Allen screws with the included tool - done! Please note: The NM-TR5-SP6 is only compatible with DX-4677, DX-4189, DX-3647 and TR4-SP3 series coolers and cannot be used with any other Noctua coolers.