Seagate SRPS20 User Manual page 41

Empty trays must stay in the bays for proper airflow.
Make certain that you are properly grounded before touching the hard drives.
Make certain that the hard drive's SATA connection is at the rear of the tray.
The hard drive is fastened to the tray with pins.
The WSS NAS is shipped with screws to mount 2.5-inch hard drives to the hard drive trays.
1. Remove empty hard drive trays from the WSS NAS.
2. Gently bend the left side of the tray and connect the hard drive to the two pins on the right.
3. Release the left side of the tray and connect the remaining two pins to the hard drive.
Seagate WSS NAS 2-Bay | 4-Bay | 6-Bay 4/13/15 41