The NA-FK1 is a second fan kit for the NH-U12S redux CPU cooler. Upgrading it to a push/pull-style dual-fan setup makes it possible to further improve cooling performance or to reduce noise levels by having two fans running at lower speeds. The kit includes a second NF-P12 redux-1700 PWM fan, anti-vibration pads, fan mounting clips, a 4-pin PWM y-cable as well as two Low-Noise Adaptors – everything you need to boost the efficiency of your NH-U12S redux! Enhanced cooling performanceAdding a second NF-P12 redux-1700 PWM fan to the NH-U12S redux makes it possible to further improve cooling performance by around 1-3°C, depending on the application. As a rule of thumb, the gains are bigger the higher the heat load, so the NA-FK1 is particularly attractive for higher-end CPUs, extensive turbo use or overclocking. Lower noise levels and acoustic fine-tuningThe NA-FK1 can not only be used to enhance cooling performance, but also to lower noise levels: by letting both fans run at reduced speeds, either via automatic PWM control using the supplied y-cable or via the included Low-Noise Adaptors, the NH-U12S redux can operate more quietly while maintaining the same level of performance. NF-P12 redux-1700 PWMThe NF-P12 redux-1700 PWM fan included with the NA-FK1 is the same high-quality unit that comes pre-installed on the NH-U12S redux CPU cooler, so it’s a perfect match for a push/pull-style dual-fan setup. Supporting PWM for automatic speed control, it can run near silent most of the time and provide massive performance when necessary.