Compatible for Synology DiskStation models: DS218+ DS718+ DS918+ DS418play. DDR3L 1866MHz PC3L-14900 204-Pin Unbuffered Non ECC 1.35V CL13 Single Rank 1Rx8 based 512x8 Module Size: 4GB Package: 1x4GB. Equivalent to an original Synology D3NS1866L-4G module. Designed for maximum compatibility and easy installation to expand your Synology NAS server's memory capacity. Guaranteed – Lifetime warranty from Purchase Date Free technical support.