Adding to its line of iconic brown fan CPU coolers, Noctua has introduced the NH-L9a-AM4 and NH-L12S for Ryzen processors. Both coolers focus on slimness for use in HTPCs and other small form factor cases.

The NH-L9a-AM4 measures in at 37mm tall, while the NH-L12S comes in at 70mm including its fan. Noctua claims that the NH-L9a-AM4 is compatible with all RAM and PCIe accessories and will not block the installation of other hardware. The latter cooler will not block RAM that is up 45mm tall by moving the fan to the top of the heatsink.

Since both coolers are targeted at small builds where noise may be of great concern, a low noise adapter is included with each. The adapter reduces fan speeds from 2500 RPM down to 1800 RPM on the NH-L9a-AM4 and from 1850 RPM to 1400 RPM on the NH-L12S for near silent operation.

Noctua notes that only CPUs with a 65W TDP of lower are truly capable for almost completely silent operation. Neither cooler is recommended for CPUs with TDPs greater than 95W.

Both coolers ship with a 6 year manufacturer's warranty and fans with 150,000 hour life spans. The NH-L9a-AM4 carries an MSRP of $39.90 while the NH-L12S starts at $49.00.