Synology DS2413 Quick Installation Manual page 8

6 Turn the hard drive tray key 90˚ counter-clockwise (to the Lock position) to lock the handles of the hard drive
trays.
7 Repeat the steps above to assemble all hard disks you have prepared.
8 The disks' positions are numbered as shown below.
Note: If you want to set up a RAID set, it is recommended that all installed hard disks are of the same size to make
the best use of hard disk capacity.
8 Chapter 2: Hardware Setup