Designed to deliver superior RAM and PCIe compatibility, the NH-D15S is an asymmetrical single fan version of Noctua's award-winning and famous NH-D15 model. Thanks to its asymmetrical design, the NH-D15S clears the top PCIe slot on most µATX and ATX motherboards. At the same time, this model with a single fan and lower fins ensures 100% RAM compatibility with memory modules up to 65 mm in height. Users who have enough room can also upgrade the sink with a 120mm fan or with a 140mm round fan on the front of the fin assembly to achieve enhanced performance in dual fan mode. Accompanied by the reliable and professional SecuFirm2 multi-socket mounting system, award-winning NT-H1 thermal compound and manufacturer's 6-year warranty, the NH-D15S is a complete, high-quality solution that combines the efficiency of the dual tower with excellent compatibility and flexible upgrade options.