FUJITSU Disk Drives MHJ2181AT - Manual (Page 43)

Installation Conditions
3-6 C141-E088-01EN
Because of breather hole mounted to the HDD, do not allow this to
close during mounting.
Locating of breather hole is shown as Figure 3.4 in both MHJ series
and MHK series.
For breather hole of Figure 3.4, at least, do not allow its around
φ
3
to block.
Figure 3.4 Location of breather