Lenovo M5800 Desktop - Manual (Page 73)

Figure 5 “Drive bay locations” on page 67 shows the locations of the drive bays.
Figure 5. Drive bay locations
1 Bay 1 - Optical drive bay (with an optical drive installed on some models)
2 Bay 2 - Primary hard disk drive bay (with a 3.5-inch SATA hard disk drive installed)
3 Bay 3 - Secondary hard disk drive bay
Chapter 7 . Locations 67