NEC S1300 User Manual page 45

Countersunk
head screws (4)
2-8 Setting Up The DAU
This Manual:http://www.manuallib.com/nec/s1300ug-disk-array-unit-user-guide.html
4. At the rear of the rack, slightly loosen the four countersunk head screws in
the side of the left rail. These screws must not be removed. See Figure 2-5.
Figure 2-5. Tightening the Countersunk Head Screws
5. Pull the inner rail toward you and engage the upper and lower rail tabs into
the rectangle holes. While holding the inner rail, screw the mounting bolts
(M5 bolts) into the threads of the inner rail. See Figure 2-6.
Figure 2-6. Securing the Inner Rail
Rail inner
Mounting bolt