Synology HAT5310-20T - 20 TB 3.5" SATA 7200 RPM Enterprise Grade HDD for Synology NAS devices. I have 6 of these drives that I had in my Synology NAS for a little over a year, but had to upgrade to larger drives. Very good condition, they have never been dropped, nor has my NAS ever suddenly lost power as I always use a UPS. Drives are wiped and sanitized and ready to go! Ships within 1 business day of purchase.