Synology D4ES01-8G 8GB DDR4 ECC Unbuffered SODIMM. Applied Models: DS1621xs+

Always select authentic Synology memory modules from local distributors for optimum compatibility and reliability. Installation of non-Synology memory modules can lead to system instability or boot failures. Synology will not provide complete product warranty or technical support if non-Synology memory modules are used for memory expansion.