This is only the key for the QNAP HDD tray SP-TS-TRAY-BLACK. This is the last one in stock at the moment. Even if it's a QNAP server, this key is not compatible with products that do not support "SP-TS-TRAY-BLACK". It can also be used with some I-O DATA NAS (QNAP OEM). 【Applicable Models】 QNAP NAS TS-121 TS-221/TS-219P/TS-239ProII/TS-239ProII+/TS-239Pro/TS-259Pro/TS-259Pro+/TS-269L/TS-269Pro TS-410/TS-410U/TS-412U/TS-409Pro/TS-409U-RP/TS-419P/TS-419U/TS-419UII/TS-419U+/TS-421/TS-420U/TS-410U/TS-439Pro/TS-439ProII/TS-439ProII+/TS-439U-RP/SP/TS-459Pro/TS-459Pro+/TS-459ProII/TS-459U-RP/SP/TS-459U-RP+/SP+/TS-469L/TS-469Pro/TS-469U-RP TS-509Pro/TS-559Pro/TS-559ProII/TS-559Pro+/TS-569L TS-639Pro/TS-659Pro/TS-659ProII/TS-659Pro+/TS-669L/TS-669Pro TS-809U-RP/TS-809 Pro/TS-859Pro/TS-859Pro+/TS-859U-RP/TS-859U-RP+/TS-869L/TS-869Pro/TS-869U-RP/TS-870U-RP/ TS-1269U-RP/TS-1270U-RP Others ※Please check the compatibility with each model yourself. First come, first served, and immediate purchase is welcome, according to Mercari's rules, even during comment exchanges. There is a possibility of a price reduction at my discretion, but I generally do not accept price negotiations. Shipping will be by regular mail (mini-letter).