Synology DS718+ 2-Bay NAS @ TechPowerUp
 

The Synology DS718+ is a high-end 2-bay NAS with good performance, silent operation, and low power consumption. Its strong advantage is that its storage capacity can easily be expanded with five additional drives (seven in total) since it is compatible with the optional DX513 expansion unit.

https://www.techpowerup.com/reviews/Synology/DS718Plus/