OWC 8GB UPGRADE: Consists of a single 8GB DDR4 2666 PC4-21300 CL19 1Rx8 260-pin 1.2V ECC Unbuffered SODIMM Memory RAM Module Upgrade Compatible with Synology DiskStation models DS3617xs And DS3617xsII. 100% COMPLIANT: JEDEC-Standard and ROHS Compliant. Warranty-Safe Upgrade. Designed and Tested to Meet or Exceed all Manufacturer OEM Specs. INCREASED PERFORMANCE: Memory Upgrades are the Most Effective and Easy Way to Boost your PC's Performance. 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.