The Synology 2x 4GB DDR4 SODIMM is designed for use with DS1621+, DS1821+, RS1221(RP)+ models, providing reliable performance and seamless compatibility. This memory module offers smooth multitasking and enhanced system responsiveness, making it an ideal choice for upgrading your Synology NAS system. With its high-quality construction and brand reputation, you can trust this Synology RAM to deliver optimal performance for your computing needs.