OWC 4GB UPGRADE: Consists of a single 4GB DDR3L 1866 PC3L-14900 CL13 1Rx8 204-pin 1.35V Laptop SODIMM memory module compatible with Synology NAS models DS218+, DS418play, DS620slim, DS718+ And DS918+. 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 D3NS1866L-4G.