Memory RAM Replacement for Synology D3NS1866L-4G Compatible for Synology DiskStation NAS Server Models: DS620slim, DS918+, DS718+, DS418play, DS218+ Backed by A-Tech's Limited Lifetime Warranty + Friendly tech support team available to help before and after your purchase Single 4GB RAM Module | DDR3/DDR3L SO-DIMM 204-Pin | Speeds up to 1866MHz (1867MHz), PC3L-14900 / PC3-14900 ( PC3L-14900S ) NON-ECC Unbuffered | 1Rx8 - Single Rank | JEDEC DDR3L standard 1.35V (Dual voltage, can operate at 1.35V or 1.5V)