2.5" SAS Hard Drive Caddy Tray for Thinksystem ST550 SR550 SR650 SR850 SR59 BF
IBM ThinkSystem. SR650 SR550 SR850 SR950 SR630 SR530 SR860. ST550 ST558. 1 SAS Hard Drive Tray Caddy. Note: This Tray is for 2.5" HDD, not for 3.5" HDD. 4 Drive Mounting Screws.