Good design and compact hard disk but the actual storage is not 4 TB it's only 3.4 TB space. Now WD started storage stoling it's not good. Approx 600 GB loss per hard disk.
Purchased it for 4850 in march 2020. Using it from more than 6 months. Nice product, compact and working fine. But don't expect much r/w speed. It generally remains below 100 mbps.