OWC 4GB UPGRADE: Consists of a single 4GB DDR3 1600 PC3-12800 CL11 1Rx8 204-pin 1.5V Laptop SODIMM memory module compatible with Synology NAS models DS1515+, DS1517+, DS1815+, DS1817 And RS815+. 100% COMPLIANT: JEDEC-Standard and ROHS Compliant. Warranty-Safe Upgrade. Designed and Tested to Meet or Exceed all Manufacturer OEM Specs. EASY INSTALLATION: In Most Cases, Installing Memory is an Easy DIY project. Watch our OWC Basic Installation Video for Help. INDUSTRY LEADING: Consumer-friendly Advanced Replacement Program and Limited Lifetime Warranty, which includes Free Tech Support by Other World Computing. Replacement for Synology part number RAM1600DDR3-4G.