. The NH-D9L is a premium grade dual tower CPU cooler that has been designed to provide excellent quiet cooling performance at a height of only 110mm. Its comparably low profile (15mm lower than classic 9cm tower coolers such as the NH-U9S) doesnt only guarantee full 3U compliance but also makes the NH-D9L ideal for compact HTPC & Small Form Factor cases that have airflow paths parallel to the mainboard. Thanks to its 95x 95mm footprint the NH-D9L clears the RAM & PCIe slots on all Intel based & most AMD based ITX mainboards. The included NF-A9 premium fan supports automatic speed control via PWM for outstanding quietness of operation & a second optional NF-A9 fan can be added for further enhanced performance in dual fan mode. Topped off with the trusted pro-grade Secu Firm 2™ multi-socket mounting system Noctuas proven NT-H1 thermal compound & full 6 years manufacturers warranty the NH-D9L forms a highly compact premium package for space-restricted applications. Low-profile tower design for better airflow efficiency While most low-profile coolers blow air towards the motherboard the NH-D9L is a tower style cooler that bows parallel to the mainboard which allows for superior airflow efficiency in cases with front intake & rear exhaust fans that create an airflow path parallel to the mainboard. NH-D9L Features 3U compatibility Whereas classic 9cm coolers with up to 125mm height fit 4U rack mount cases the NH-D9 Ls reduced height of 110mm allows it to also fit 3U chassis. This makes it absolutely ideal for noise-sensitive 3U applications in fields such as audio or video processing. NH-D9L Features 100% RAM compatibility With its 95x 95mm footprint the NH-D9L does not overhang the RAM slots on current Intel & most AMD mainboards. This gives the user full access to the memory modules & guarantees 100% compatibility with tall heatspreaders or optional memory fans. NH-D9L Features 100% compatibility with PCIe cards on mini-ITX Many Intel LGA115x based mini-ITX mainboards have the PCIe slot sitting right next to the 95x 95mm socket zone. While larger coolers that exceed this zone are likely to block the PCIe slot the 95x 95xmm sized NH-D9L provides full compatibility with PCIe cards be it on ATX micro ATX or ITX..