04-14-2021, 08:07 AM
Qnap TS-251D supports these two cards :QXP-800eS2 x SFF-8088 port(SATA),PCIe Gen3 x4 (32 Gbps)expansion cardQXP-400eS1 x SFF-8088 port(SATA),PCIe Gen3 x2 (16 Gbps)expansion cardhttps://www.qnap.com/en-uk/compatibility/?device_category=expansion%20card&brand=qnapSo based on that tl-d800s and tl-d400s should work.But Qnap also list D1600S on the compatibility page - so I guess all of them would work .Supported Expansion Enclosure for TS-251DModel NameForm FactorInterfaceMaximum Connected NumberNoteTL-D1600STowerSATA 6Gb/s (SFF-8088)1TL-D400STowerSATA 6Gb/s (SFF-8088)1TL-D800CTowerUSB 3.2 Gen 2 (Type-C)1TL-R1200C-RPRackmountUSB 3.2 Gen 2 (Type-C)1TL-R1200S-RPRackmountSATA 6Gb/s (SFF-8088)1TL-R400SRackmountSATA 6Gb/s (SFF-8088)1TR-002TowerUSB 3.2 Gen 2 (Type-C)2TR-004TowerUSB 3.2 Gen 1 (Type-C)2TR-004URackmountUSB 3.2 Gen 1 (Type-C)2https://www.qnap.com/en-uk/compatibility-expansion?model=ts-251dI hope this helps.