Synology Plus Series HDD 4TB, Internal 3.5' SATA, 5400RPM, 3 Year Warranty Minimum DSM version requirement: DSM 7.1.1-update 4. Supported NAS models include: 25 Series - DS225+, DS725+, DS425+, DS925+, DS1525+, DS1825+ 23 Series: DS923+, DS723+, DS423+, DS423, DS223, DS223j, DS123 22 Series: RS822+, RS822RP+, RS422+, DS2422+, DS1522+, DVA1622 21 Series: RS1221+, RS1221RP+, DS1821+, DS1621+, DVA3221 20 Series: RS820+, RS820RP+, DS720+, DS420+, DS220+, DS420j, DS120j, DS220j 19 Series: DS119j, DVA3219 18 Series: DS1618+, DS418, DS418j, DS218, DS218play, DS118 Expansion Unit: RX418, DX1222 , DX517 Technical Support / Warranty - Please log a Synology Ticket. Capacity 4TB Rotation Speed 5400 SATA 6Gb/s Warranty- 3 Year Limited