OWC 8GB UPGRADE: Consists of 2pcs of 4GB DDR3L 1600 PC3L-12800 CL11 1Rx8 204-pin 1.35V Laptop SODIMM memory compatible with Synology NAS models DS1817+, RS818+, RS818RP+ And RS1219+. 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 RAM1600DDR3L-4GBx2.