OWC 16GB UPGRADE: Consists of a single 16GB DDR4 2666MHz PC4-21300 CL19 2RX8 ECC SO-DIMM 1.2V 260-pin Memory Module Compatible for Synology NAS DiskStation RackStation FlashStation & NVR DVA Servers models: DS1522+ DS1618+ DS1621+ DS1621xs+ DS1819+ DS1821+ DS2419+ DS2419+II DS2422+ DS3018xs DS3617xs DS3617xsII DS3622xs+ DVA3219 DVA3221 FS1018 RS1221+ RS1221RP+ RS822+ RS822RP+ INCREASED PERFORMANCE: Memory Upgrades are the Most Effective and Easy Way to Boost the Performance of Your Server Micro Server or NAS System INDUSTRY LEADING: Consumer Friendly Advanced Replacement Program and Limited Lifetime Warranty which Includes Free Tech Support by Other World Computing EASY INSTALLATION: In Most Cases Installing Memory is an Easy DIY project. Watch our OWC Basic Installation Video for help.